IntelliJ - show where errors are

Question: Is there a way to make IntelliJ mark error locations continuously for the files you are working on in the similar manner as Eclipse does? At the moment I need to make the project which lists all the errors in the message panel, but even then I cannot navigate to them using the editor panel. I would like to have simple dots/markers which would point to error/warning locations.
Comment: Any chance you have the "Power save mode" enabled by mistake?
Comment: That happens by default in Intellij. Are you sure it's identifying your source files correctly ?
Comment: I can see warnings but not errors...\
Comment: I am using a different color scheme. Is there a place to edit that behaviour, as mine is simply grey and I cannot see it on the highlight bar
Answer: IntelliJ IDEA detects errors and warnings in the current file on the fly (unless Power Save Mode is activated in the File menu).
Errors in other files and in the project view will be shown after Build | Make and listed in the Messages tool window.
For Bazel users: Project errors will show on Bazel Problems tool window after running Compile Project (Ctrl/Cmd+F9)
To navigate between errors use Navigate | Next Highlighted Error (F2) / Previous Highlighted Error (Shift+F2).
Error Stripe Mark color can be changed here:
Comment: "Errors in other files and in the project view will be shown after Build | Make and listed in the Messages tool window."  Unfortunately the output in the messages window doesn't tell you where the error is, it just tells you the compilation failed, and to see compiler error output for details. Is there any way to make it show the compiler error output from within the IDE instead of running from the command line?  Also it would be great if files with a problem could be marked somehow in the file tree so you could see files which had errors even when they weren't open.
Comment: Is there somewhere a list with this errors? (a list with the errors I can jump to by pressing F2
Comment: In my case, the "Error stripe mark" box under `Settings | Editor | Colors & Fonts | General | Errors and Warnings | Error` was unchecked. Checking this box fixed the issue.
Comment: For me (with AndroidStudio 3.1.2) errors are shown in _View > Tool Windows > Build_ after _Build > Rebuild Project_ but files are still not marked. I've opened a question for this: https://stackoverflow.com/q/49835192/2532583
Comment: @markthegrea please [submit a ticket to support](https://intellij-support.jetbrains.com/hc/requests/new) with more details.
Answer: For those who even yet have the problem, try enabling "Build project automatically" in the Java compiler settings and see if that makes a difference as it worked for me.
Comment: Thanks! Although this is not what the OP strictly asked, this makes IntelliJ to show the list of errors as most IDEs do.
Answer: I ran into the problem of not having set my sources root folder (project window--right click folder, mark directory as > sources root).  If you don't set this IDEA doesn't parse the file.
Answer: For IntelliJ 2017:
Use "Problem" tool window to see all errors.
This window appears in bottom/side tabs when you enable "automatic" build/make as mentioned by @pavan above (https://stackoverflow.com/a/45556424/828062).

To access this Problems panel, you must set your project to build automatically. Check the box for Preferences/Settings > Build, Execution, Deployment > Compiler > Build project automatically.
Comment: No such menu item in IntelliJ 2019.1.
Comment: @BasilBourque  you need to check the Build Project Automatically checkbox under the Preferences -> Compiler and restart IntelliJ 2019.1
Answer: Frankly the errors are really hard to see, especially if only one character is "underwaved" in a sea of Java code. I used the instructions above to make the background an orangey-red color and things are much more obvious.
Answer: In IntelliJ Idea 2019 you can find scope "Problems" under the "Project" view. Default scope is "Project".
Comment: This only shows the problems that are already found. Does NOT analyze files to check if there are any problems.
Answer: Besides, you can choose going to next error only (ignore warning) by:

Right click the Validation Side Bar.
On the context menu, choose the Go to high priority problems only

it works for Intellij Idea 12
Answer: In my case, I unknowingly unchecked 'Error Stripe Mark' option (Idea 2018.2: Settings > Editor > Color Scheme > General and expand `Error and Warnings' & click 'Error').
Fix is to check 'Error Stripe Mark' option of 'Error' (as highlighted in the below image). Now you will see the error marks in scrollbar area.
Answer: In my case, IntelliJ was simply in power safe mode
Answer: Do you have a yellow icon like this [_] at the bottom of the main window?
It is a "type-aware highlighting" switch which could be disabled accidentally.
You should re-enable it by clicking on the icon.
Answer: In the intellij hit ctrl+alt+shift+s and go to global libraries and click on plus icon to add the java libraries this will solve your problem. now you will see the errors coming up
enter image description here
Answer: This is the solution I found:

Open IntelliJ Setting (Crtl + Shift + A);
Click in "Editor";
Click in "Color Scheme" + the Programming Language (inside "Color Scheme");
Select "Analysis Error";
Select "Error stripe mark" + Add the Color desired
Comment: This just sets how errors and warnings will be displayed, but it does not automatically buil d the project to have all errors/warnings marked in their corresponding files/lines, like Eclipse does and what is being asked.

IntelliJ - show where errors are


Effects of inner painting in the temperature of room

Question: which room will stay warmer for long time in winter night. The room with inner painting black or white?
Comment: If lights are off (night), then the color of the paint in the visible domain is pointless. Do you know which of those two is the most reflective in the infrared ? :-)

And with the light on we would need more knowledge, since direct and reflected light can leaks from the windows while energy of heated walls can leak via its connections to the exterior (and insulation might be settle at different possible steps). So all data related to all possible leaks are needed.
Comment: Black is a good absorber and bad radiator of heat. White is a good reflector of heat. Now you decide what should the answer be.
Answer: It will make no measurable difference.
Heat in a room is lost by conduction and convection - not (in significant amounts) by radiation.
Radiative heat transport occurs between two objects at different temperatures, so the surface of the wall would have to be colder than the rest of the (objects in the) room for radiative transport to take place.
Assume a black sphere in the middle of the room at temperature $T_1$, and a wall at $T_2$. If the walls are "black" (maximum emissivity at the wavelengths of interest - note this is not just black in the visible since most thermal radiation is in the far IR) we can compute the rate of heat loss as
$$Q = \sigma(T_2^2-T_1^2)\pi r^2$$
For a wall at 0C and a sphere at 20 C, this results in heat transport of about 100 $\rm{W/m^2}$ from the object to the (perfectly black) walls. In reality there are not walls on all sides - so the solid angle is smaller and the rate of heat transport is less - and furthermore the walls are not that cold. Because if they were, there would be significant heat transport from the air.
For this you can refer to this engineering toolbox link. With a very modest rate of air flow you will have a heat transfer of about 20 W per square meter per degree of temperature difference. This would quickly result in a heating up of the wall surface to "something close" to the temperature in the room - at which point the radiative losses are even smaller.
It may already be obvious from the above but let me spell it out: radiative cooling would (very slightly) affect objects in the room; but the air has very little radiative interaction.
At "normal" temperatures, and with a house that is somewhat insulated, you can ignore the radiation component. This is not necessarily true if you have a flimsy tent - you may have come across the aluminized Mylar "emergency blankets" that provide radiative insulation. They do make a difference when that's all there is between you and a cold dark clear sky. Not the same thing at all.
Answer: The scientific fact is that white reflects the radiant energy rays of the sun and black absorbs them.
Most major paint manufacturers can tell you the Light Reflectance Value (LRV) of any color paint chip. White reflects 80% of the light, black 5%.
So if you want to have a warmer room paint it black since more of the radiant energy of the light will be absorbed to keep the room warmer.
Comment: At night it will not absorb heat from outside, rather inside heat is absorbed and transmitted outside via wall.so inner painting should be white.
Comment: @Rajeshkumar: The problem is deceptively simple, with the stress on the word "deceptive" (this has connotations for the politics of global warming because it leaves the door open for plenty of false explanations of radiation forcing). The important parameters for your problem are the radiation temperatures of day and night. The radiation temperature of "day" is around 5600K, while that of night is around 300K. What matters are the "colors" of the paint at the peaks of the Planck curves for these two temperatures.


Training punching vertically pad on the floor

Question: Instead of punching horizontally some pad/sack/dummy on a wall or hanging from the ceiling, could we place a (properly cushioned) pad on the floor and train punching it (the position would be like a one-hand push up)?
Comment: What are you trying to achieve with this training setup?
Comment: Punching sometging on the ground? I would recommend only hammer fists, as they are the most safe way to do in that setup.
Answer: Can you...sure you can, but you defeat the body mechanics and technique which is the main goal of the training.  Punching a standard bag or wall pad allows you to position your body and punch with pivoting as well as proper technique to train your body to punch properly as well as increase your skill and power.  On the ground like you mention you eliminate your lower body and pivoting for the punching.  You also eliminate your upper body except for 1 arm because you have to hold yourself up with the other hand.
If your limited on means it would be better to hang a pad by a string and practice proper technique even if you can't see the power due to little resistance than it would be to mess up the body mechanics and practice bad form.
Answer: Yes, you can.  Indeed, there are human-shaped targets that the MMA guys at my gym often sit on top of while working on their downward punches, or even wrapping themselves around it from underneath and hitting into the kidney area.  While mutt's right that a standing punch lets you engage more muscles and get more power, that's no reason not to practice punching from other positions where it may still be your best or only option.  The more versatility you have using your techniques, the better.  It's not to "practice bad form", but to understand how the form should best be varied with your and your opponent's position.  That said, if you don't have a good standing punch, it may be a good idea to work on that first - it will give you a better idea of what bio-mechanical elements you should at least be trying to utilise from a more prone position.  And a "one handed pushup" position doesn't sound like something coming about often during ground fighting anyway....
Comment: a "one handed pushup" position doesn't sound like something coming about often during ground fighting anyway...  :) that made me laugh, like some super hero show off move once you have the guy down do a one handed pushup and hit him down with full intimidation :)
Comment: @mutt: Jet Li's early movies had several scenes where he was bouncing around doing one arm pushups in the middle of a fight, but usually he'd just been thrown then was avoiding attacks to each of his arms in turn.  I keep meaning to practice it as it's so obviously useful (as long as they kick at your arms and not your head) but somehow always forget to. ;-)
Answer: Can you practice punching a target on the floor? Yes, you can.
Should you?
Yes, if you want to get good at punching an opponent on the ground (say, who you have just thrown).
It doesn't seem like it would be a good substitute for practicing a punch for situations where both you and your opponent are upright. The body mechanics are quite different.
Since your question included the phrase "instead of," I would answer that it would not be wise for this to be your primary punching practice. Always practice in a way that most closely resembles the circumstances in which you expect to deploy a technique.


How to calculate sample size for blocked-design two-way ANOVA?

Question: Does anyone know of a good online calculator or at least a good paper that details how to calculate the needed sample size for a blocked-design two-way ANOVA experiment?  I've seen a ton of references showing how to analyze the data from such an experiment, but none about how to properly design  it and estimate the required sample size.  Thank you!
Answer: As for a good reference, I would suggest Ryan, T.P., Sample Size Determination and Power, Wiley, 2013. It covers pretty much everything regarding the comparison of means and proportions, regression settings, and a large amount experimental designs.1 Randomized Complete Block Designs are treated in $6.2.5.
Power analysis in this case generally relies on the noncentrality parameter, which varies from one design to the other. Usually, you have to specify $\sigma^2$ (variance of the individual observations under the null hypothesis) and theoretical means for each block. The Java applets for power and sample size has some utilities to work with this kind of design (via the "Balanced ANOVA" menu dialog).

Sidenote: Blocking reduces the degrees of freedom for the error term, which reduces power, yet a randomized complete block design (RCBD) is generally more powerful than a completely randomized design.
1 Giesbrecht & Gumpertz, Planning, Construction, and Statistical Analysis of Comparative Experiments, (Wiley, 2004), is cited by this author but I haven't read this book, so I can't say anything.


Is it worth upgrading my companion's gear in Skyrim?

Question: Just getting started with companions.  Should I be evaluating their gear and transferring upgrade items to them to improve their performance?
Answer: The game will decide for you what they should wear: they'll always try to equip the best stuff they have. It is worth giving them upgrades, especially if you don't plan on getting them killed.
One thing to keep in mind: you can't teach an old follower new tricks. If your follower thinks, acts, and combats like a mage, giving them a two-handed axe or heavy armor isn't going to be at all useful for them because they aren't going to get better at axes or wearing heavy armor, even though they will choose to use it in lieu of magic.
Comment: @faB I don't know of a non-console way to know what skills they prefer (with the exception of when the follower is also a trainer), but [UESP has the list](http://uesp.net/wiki/Skyrim:Followers) (confirmed by the strategy guide).
Comment: Is there a visual cue in game for a follower's skill increase? Or is this something only verified through console commands?
Answer: There seems to be a limit to how much you can upgrade a follower's bow, as I found out the hard way.
I made a Legendary Daedric Bow and gave to my follower (which was an upgrade from her Legendary Glass Bow) and she instead skipped it and started using the Hunter's Bow she started with. I believe the highest bow combo an NPC will use is Glass Legendary + Iron Arrows — any higher combination and they will default to the lesser Hunter's Bow. I hope to find out more as I experiment.
Comment: I gave Lydia *one* glass arrow, and she uses that as her ammo. Since I use Steel arrows myself, and every now and then find Glass arrows in the victim's bodies, I can say with certainty that she is using them. It also shows as equipped in her inventory, *when she is currently equipping the bow*. With that said, on another character I gave a Steel arrow to Jenassa and she wouldn't use it. The arrow disappeared so I figure she spent it, but she would not "magically" restock on that same arrow type. Perhaps it is her Falmer bow that caused this issue. It may be based on level and item level.
Answer: Even worse, some followers--especially archers--don't have certain skills, like heavy armor, block, or two handed.  But, these characters will equip and use these items anyway if you give them to them.
I've solved this by smithing and enchanting nice items of the appropriate type.  This seems to solve the problem for a quite a while, until I accidentally asked him to carry an iron dagger for vendor fodder--even though he had a legendary enchanted bow--and watched him charge a giant.  facepalm
A small note--it doesn't seem that giving soul gems and a soul trapping weapon to a follower works for collecting those low level petty souls that these characters constantly kill before you can get a shot off.  The effect goes off, the animal dies, no soul gem filled.
Humorous side note: the ragdoll effects of watching your tactless follower fly hundreds of feet into the air after being crushed by a giant are amazing.  Serves him right.


L1 L2 regularization

Question: The tutorial says the intersection point for L1 and L2 regularization gives the minimum loss - But why the intersection gives the minimum loss? I cannot interpret the graph clearly.
Comment: Possible duplicate of [Lasso regression feature selection](https://stats.stackexchange.com/questions/324145/lasso-regression-feature-selection) or https://stats.stackexchange.com/questions/45643/why-l1-norm-for-sparse-models/364931#364931
Answer: One way to view both ridge and the lasso is as the solution to the constrained equation
$$
\widehat \beta = \operatorname{arg min}_{\beta} \|Y - X\beta\|^2_2
\quad \text{subject to $\|\beta\| \le \eta$}
$$
where $\|\cdot\|$ is, in either case, the $\ell_1$ or $\ell_2$ norm. The usual penalization characterization of this
$$
\widehat \beta = \arg \min_\beta \|Y - X\beta\|^2_2 + \lambda \|\beta\|_p^p
$$
($p = 1$ for the lasso and $p = 2$ for ridge) is just the formulation of the optimization in terms of a Lagrangian, where $\lambda = \lambda(\eta)$ is a function of $\eta$. Anyway, once you have the constraint formulation, it should be clear why the solution is the intersection: we are finding the contour with the smallest value which satisfies the constraint. The points inside the $\ell_1$ or $\ell_2$ ball are the points which satisfy the constraint, and we want to pick the solution $\widehat \beta$ which is on the contour of smallest value. When the least squares solution does not lie in the $\ell_p$ ball itself, this will occur on the boundary, where one of the contours intersects the boundary of the ball.
Comment: Thanks, when they are separated say $$\widehat \beta = \arg \min_\beta \|Y - X\beta\|^2_2$$ and $$\widehat \beta = \lambda \|\beta\|_p^p$$ I suppose the solution will be the center for the square and ellipse (for L1), and the center for the circle and ellipse (for L2). What I am still not very sure is when they sum together, why the solution lies in their intersection and not some non-intersection point?
Comment: @william007 Again, you want to think of it as constrained minimization, not in terms of the Lagrangian, if you want to get this straight. There is no ball directly associated with the Lagrangian. If you give me the Lagrangian, I cannot give you the corresponding circle, at least without you also giving me the data. It is only through the formulation as a constrained optimization that you get this: there *exists* a $\lambda$ such that the constrained optimizer is the solution to the optimization.
Comment: Thanks guy, and thinking in terms of constrained optimization, why the solution lies on their intersection, but not non-intersection points?
Comment: @william007 it must lie in the ball by definition; that literally is what the constraint is saying. There are two possibilities: either the unconstrained optimizer is in the ball (in which case it is also the constrained optimizer and is not necessarily on the boundary), or it is not, in which you cannot use it. In the latter case, you need to find the value of the objective which is minimal and lands in the feasible region, which can be done by finding the first countour which intersects the ball.
Answer: Minimizing the loss function $f(\theta)$ with regularization function $g(\theta)$ can be viewed as minimizing a  Lagrange Function.
$\mathcal{L}(\theta,\lambda) = f(\theta) - \lambda \cdot g(\theta)$
you can then minimize by taking the gradient
$\nabla_{\theta,\lambda} \mathcal{L}(\theta, \lambda)=0$.
In a Lagrange Function, the optimum occurs when the gradient of the loss function is perpendicular to the regularization function.
$\nabla_{\theta} f = \lambda \nabla_{\theta} g,$
Here is a much better explanation by Dikran Marsupial :What is the connection between regularization and the method of Lagrange multipliers ?
Just a note it this is a very general explanation.

L1 L2 regularization


Why do I have -1 rep on a downvote after hitting the rep cap?

Question: I apparently hit the rep cap today since the last up vote only gave me +1 rep. Still, after making a down vote my rep is reduced by 1. I was expecting it to show no reputation change. Am I missing something?
Comment: You mean that you expect to have a sort of "surplus" of 9 rep that should be able to absorb negative rep changes?
Comment: While it sounds like Eugene is being selfish about having extra rep, it sort of makes sense. Had he made the downvote before he got an upvote, he would have gotten +2 rep and then still hit the rep cap. Why should it matter which happened first, if they were on the same day?
Comment: @McAdam331: Not saying it's right or wrong, but it's also consistent with what happens on the other end. If you post an answer at rep 1, then get 3 downvotes followed by an upvote, you wind up with more rep than if you had gotten the upvote first followed by 3 downvotes.
Comment: @Josh: yes, exactly. Just like any upvotes show no reputation change after reaching the cap.
Comment: Sounds fair to me. You only get 1 rep due to the cap, those extra 9 never exist. Any subsequent rep-reducing action you take later subtracts as usual.
Comment: @CubeJockey: I think it depends on how you look at it. To me it would be fair to have the mentioned 'surplus', equal to the amount of 'lost' reputation in the given day.
Comment: @JohnY that's a really good point.
Answer: The rep cap is not applied to the sum of all transactions that take place in that day, but rather on every individual transaction.  Any time you would gain rep, any rep that would put you beyond the rep cap is lost, forever, at that instant.
Comment: @RobBaillie It's not a bug, it's by design.  You may not like the design, but that doesn't make it a bug.  If you pour 2 cups of water into a 1 cup container, and then pour out half a cup, would you expect the container to still be full because you poured 2 cups in and only took 1/2 cup out?  Would you thing that the order doesn't matter when adding/removing water into the container?
Comment: There's also the oddity that order will have an effect.  I.E. if you get all your upvotes to max out your rep, and then one downvote, you'll get -1 applied.  You get a downvote and then all your upvotes you get the max.  Why should the order have affect the total if the number of ups and downs are the same?  By design or not, it sounds like a bug to me.
Comment: Something to remember is that this works both for gaining rep and losing rep. For example if a new user makes a posts and gets a couple of down votes and later an up vote they will not lose any rep from the previous down votes even though they now have rep they can lose.
Comment: I'd just be happy to have received so many _meaningless internet points_ that they stopped counting...
Comment: @pnuts When votes are undone, possibly through the deletion of a post, the way it resolves such removals is to essentially answer the question of, "what would your rep had been if this action had never happened in the first place?" So if an upvote is lost due to a deleted post/user, it's possible to have no effect on your rep, if you still end up hitting the rep cap when viewing the world as if that post/user had never existed.  Note that this doesn't result in you *gaining* rep, it just results in you not losing it.
Comment: @eugeney a rep recalc is just correcting for errors in the computation of the rep total.  If the system hadn't made an error in the first place, there would be no rep changed.  Keep in mind that all of the root information from which the reputation is derived is still kept, which is why you can recalculate rep in the first place.
Comment: @Servy Using an analogy to prove a point of functional design misses an important point, I.E. you can come up with an analogy to prove *any* point.  How about instead taking the design to the extreme?  I post an answer that gets 5000 up votes, then 200 down votes.  Presumably I get zero for the day.  If I get 200 downs and *then* 5000 ups I get 200.  That doesn't feel like it's right.  As I said in my earlier post, I *get* that's the design, I just suspect it's a technical design that has led to a functional oddity that has been accepted rather than a true functional design decision.
Comment: @pnuts That is correct.
Comment: Is it really lost *forever* ? I remember at least one [reputation recalc](https://blog.stackoverflow.com/2010/03/the-great-reputation-recalc-begins/) on SO.
Comment: @RobBaillie This isn't some new discovery that nobody has noticed before.  This has been brought up many times.  SE has made it clear that this is the intended design.  If you want to propose a change to the design, then feel free to write a proposal, and explain why the benefits of making the change that you want would merit the time spent and any negative consequences.
Answer: Just like when you post answer when starting out, and you get down-voted, then you post a better question, and it gets up-voted, then you have 6 rep.

Here's a list of the events and the order in which they happen in (from my example above):

You make an SO account.
You ask a bad question.
Your question is down-voted.
You "lose" 2 Rep.
But your Rep is still at 1.
You learn from your mistakes.
You ask a better question.
It gets up-voted.
You now have 6 Rep.
And so on.

As you can see, if you would add up Rep at the end of that day, you would have 4 Rep (1 - 2 + 5 = 4), but you have 6 because SO's system adds it up as you go and doesn't ever go negative (1).
I know this wasn't exactly what you where asking, but I think it draws a very good analogy, and I felt this needed to be added.
Hope this helped!

References:
(1)

All users start with one reputation point, and reputation can never drop below 1.

Found Here: stackoverflow.com/help/whats-reputation


Are there any comprehensive video courses or lecture notes on Industrial robotics?

Question: I am really new to the topic. There doesn't seem to be lot of overlap between Industrial robotics and Hobby robotics (atleast in certain areas like control etc).Please correct me if i am wrong. I actually tried going through Fanuc website, and most of the content is restricted. I would like to know if there is any course on how to operate Industrial robots? its PLC programming? or any application specific course etc?
Answer: To directly answer your question, you can take a look at some of the ROS MoveIt! Videos. Check out the Udacity robotics courses.

To give a more opinionated answer...
I've worked both with industrial robots and mobile robots, so my opinion is that if you learn mobile robotics concepts including manipulators and become familiar with robot system design, you'll be able to do well in industrial robotics. However, industrial robots are typically programmed in a very different way.
Mobile robots are designed to sense and respond to their environments.
Industrial robots are primarily designed to follow pre-planned instructions and manipulate their environments.
So industrial robots are typically not designed with a wide array of sensors and complex conditional logic. It's a lot of sequential programming in specialized languages such has RAPID (ABB), KUKA Robot Language, KAREL, Fanuc TP (each robot manufacturer has its own, and there are some industry standards). It's a lot more like CNC programming, but without G and M code and rather a list of human-readable sequential steps. You can watch YouTube to get up to speed on any of these languages, but none of them are that revolutionary. If you're already a programmer, you'll probably cringe a little and roll your eyes when you see these languages.
The skills in mobile robotics transfer over, and you can even make big improvements to the industrial robotics world by bringing in the more traditional skillset (which sensors, algorithms to use, metrology, etc.)
Most training on industrial robots is either done at universities that have partnerships with the robotics companies or at companies that have purchased these robots. Thus it's hard to get into the details of this field without being there. But you're not missing much in my humble opinion. I've been through those trainings and I mostly rolled my eyes because industrial robotics seems to be miles behind the rest of the robotics industry in terms of how the user would program them. Thus just learning robotics in general will help a lot.
Most industrial robots just perform DSP on the motor signals to figure out where they are. It's amazing and kind of scary, but there's no physical positioning feedback. The error adds up through the chain out to the end effector and it's a pain. Some of the more advanced robotics groups thus measure the end effector from the outside to correct these estimates, and that's done with expensive software rather than someone actually programming anything.
In general, if you learn MoveIt!, you've read about robotic arm path planning, and you are familiar with robotics concepts in general, you'll be ready to jump into the world of industrial robots, and you might even cringe a little when you see how the robots that run factories really work.
Comment: I mostly agree. I do not agre with ros mentioned as an example for learning to deal with industrail robots. Also industrial robots do not perform DSP on motor signals to figure out where they are. They have encoders in all joints and can achieve 10 micron positioning precision. The reason they do not have an external camera system is: they do not need one. There is no "traditional skillset" that is missing in industrial robotics as you mentions. Moreover, industrial robot companies enter the mobile robotics markets, and not the other way around
Comment: Furthermore do not underestimate industrial robotics. They are behind research, this is true for all fields, not just robotics. However, they have advanced capablities needed in the industry. E.g. countour finding for welding applications, builtin state machines for easy task dispatching from externally connectes cell controllers, cooperation functions where one robot works in the moving reference frame os a different robot.
Comment: The KUKA robots I worked with had no encoders- 100% of the pose data came from DSP, according to the KUKA reps I worked with. Same w/ ABB.

The traditional robotics skillset includes programming a robot to perform Bayesian state estimation, sensing, and decision making. Industrial robots in my experience almost never use these skills, but rather are programmed purely imperatively. Do x, do y, do z, go here, come back. Thus path planning knowledge is somewhat relevant, but it's almost always done offline, and almost always done by prebuilt software GUIs, not by a programmer writing code.
Comment: I would say that because industrial robotics is "good enough" with this offline-planned method and factories can get good enough consistency that these pre-planned paths are highly reliable even with no sensors at all, it stifles innovation in the field. Industrial robots don't take advantage of all the great robotics technology in the rest of the industry that's a bit more cutting edge. Responding dynamically to sensor data isn't "research," it's a tenant of robotics, and one only very new industrial robots are beginning to take advantage of, outside of safety applications.
Comment: And I totally agree with you that there are a few really great emerging technologies in industrial robotics and it's starting to catch up, but the majority of industrial robots I've interacted with aren't so glorious, and those that are... are very buggy!
Comment: Older Kuka Robots did not have encoders, but still, the position information did not come from motor signals, but from resolvers. The resolver signal has to be processed but it is not a pose estimation from motor signals.
Comment: It was a brand new Titan. Not sure, I might have misunderstood, but they said it was effectively really fancy dead reckoning.


First fight with Nemesis problem

Question: I played Resident Evil Nemesis a long time ago but was stuck on the first fight with Nemesis. My health was low then, and I couldn't find a way to defeat him. I tried to find some cheats that will skip that fight but couldn't, so I had to stop playing the game. I want to play this good game, so can anybody tell me the way to defeat him with very low health or some cheats to skip the fight? thanks in advance friends.
Answer: You can try run by his right side, he will try to hit you with his left side. Once you passed him not too far or he will chase you, turn around and shoot him. Nemesis will fall but will get up again, so keep doing this until he falls and starts bleeding (purple blood).
Answer: Yes, you stick to his right and run past him, turn around and blast him when he gets close. I think that pressing o at the right time will make you dodge by rolling away. You can avoid the fight completely by running into the station.
Answer: There is a series of videos called the "Handgun/Knives Challenge" that detail how to defeat nemesis using only the handgun and knife. Part 1 covers how to defeat him in the first battle outside the RPD. In general, there are several tips the author of the video outlines:

Nemesis is left-handed. That means he'll punch and try to grab you with his left hand. You brush past his right shoulder to avoid getting grabbed. According to File 2, Nemesis needs to be on your left side to grab you.
When he goes to grab you, you can time your shots to dodge his grabs.
When he runs at you, it's possible to dodge, although difficult. It's best to run around and try to avoid his punch, and do a back-stutter (where you stop running and go backwards for a second, like you do when you dodge a zombie.)
Don't back yourself into a corner. If you do this, you'll be unable to dodge, or you'll dodge into terrain. Even if you do dodge, Nemesis will have you pinned and grab you.

Nemesis can glitch on the terrain, allowing you to take pipe shots at him. It's most obvious in the second battle where you're in Martin Branagh's office. He'll keep walking into the shelf while you shoot at him. It can happen in other places although it is more difficult to reproduce.
The important thing is to keep your distance and minimize the amount of time you spend standing still. You might be frustrated at not being able to get in enough shots before nemesis grabs you. Never let Jill automatically reload, always reload from the inventory. Keep your finger on the trigger if you plan on shooting, and release it immediately if you plan on running. The draw animation wastes precious time which allows Nemesis to catch up to you.

First fight with Nemesis problem


How to detect who kills a certain player?

Question: I'm making a juggernaut game in Minecraft, and I need to know how to detect when someone kills the juggernaut and then do something to that player (like set a dummy objective "juggernaut" to 1 for that player).
Answer: Simply change the objective type to stat.teamkill.dark_red (or other color)
Place the juggernaut on a team and set that team's color to match the objective criteria
When you end the game, use the selector @p[score_Juggernaut_min=1] to find out who won.
Comment: I totally forgot that there is a scoreboard objective that goes up when you kill a player on a certain color team, I recommend using this instead.


what is the distance a service drop needs to be from windows

Question: Hi thank you everyone for your awesome input and help. I'm trying to decide placement for service drop to new electrical service panel/main circuit breaker panel. this is new construction of a two story house and I'm hoping to place it on side wall in between two windows that my service drop pipe has a straight shot up the wall thru the 2nd floor and out the roof. there is only 24" on each side of panel then windows.
Comment: Are you asking about the actual service drop conduit, or the electrical panel?
Comment: both. I think the panel is ok to be in location but not sure about conduit coming down inside of wall so close to windows?
Answer: The raceway for the service conductors can be where you want. Here is the pertinent National Electrical Code language:

230.9 Clearances on Buildings.  Service conductors and final spans shall comply with 230.9(A), (B), and (C).
(A) Clearances.  Service conductors installed as open conductors or multiconductor cable without an overall outer jacket shall have a clearance of not less than 900 mm (3 ft) from windows that are designed to be opened, doors, porches, balconies, ladders, stairs, fire escapes, or similar locations.
Exception: Conductors run above the top level of a window shall be permitted to be less than the 900 mm (3 ft) requirement.

Notice this actually refers to the service drop conductors not the conductors down the side of the building. "Open conductors" is the old three wire service drops and "multiconductor cable without an overall outer jacket" is triplex. These are both used for the actual service drop. Once you hit the house and transition to SE cable or a raceway you can put the service where you want as long a step it is adequately supported.
Your conductors are in a raceway and as long as the service point itself has a 3 foot clearance from the windows horizontally you are good.
Now, you said "up the wall" so I presume you are attaching your raceway on the outside of the house. That would be the normal method. Then up through the eave to the service point. Passing the service through the wall before it is protected by a breaker or fuse is a Code violation. The service is supposed to remain outside the home until it reaches the closest point to the main disconnect. Your inspector may have some specific Code interpretation about passing through the eave. This is usually allowed if it just a small slope at that point and is a non-habitable part of the home such as an attic.
Good luck!
Comment: ArchonOSX  Thank you so very much have a great day! I truly appreciate you.


General formula for $\sum_{n=0}^\infty \frac{1}{(an+b)^c}, a> 0, b>0, c>1$

Question: Is there a general formula for this sum? $$I(a,b,c)=\sum_{n=0}^\infty \frac{1}{(an+b)^c}, a> 0, b>0, c>1$$ I noticed that the first few a, b, and c values yielded seemingly different results, but all look related in some way to the zeta function. Here are a few values of I. $$I(2, 1, 2)= \frac{\pi^2}{8}$$ $$I(2, 1, 3)= \frac{7\zeta(3)}{8}$$ $$I(3, 1, 2)= \frac{\psi^{(1)}(\frac{1}{3})}{9}$$ $$I(1,2,2)= \frac{\pi^2}{6} - 1$$ $$I(\pi,\pi,\pi)= \frac{\zeta(\pi)}{\pi^{\pi}}$$ Don't pay too much attention to the bounds for a and b as I don't really know if anything changes should the values be negative. Perhaps if a general formula does not exist, maybe one does when fixing certain values such as setting b = 1?
Comment: no, there isnt a closed formula for that
Comment: Some special values can be obtained through the zeta function, e.g. $a=1, b=0$. For example, for $n \in \Bbb N$

$$\zeta (2n)={\frac {(-1)^{n+1}B_{2n}(2\pi )^{2n}}{2(2n)!}}$$

$${\displaystyle \zeta (-n)=(-1)^{n}{\frac {B_{n+1}}{n+1}}}$$

Other identities can be found at https://en.wikipedia.org/wiki/Riemann_zeta_function. .
Comment: But I imagine you already know the previous going by the tags and some of the values. To my knowledge there is no closed form known for odd integer inputs of the zeta function (maybe part of why Apery's constant, $\zeta(3)$, is not known to be transcendental or not). Which, in light of that, (a) might mean this question will likely not yield anything more than partial answers and (b) might be better off on Math Overflow, but that's just a guess. At the very least it would be a very nontrivial question and I'm not the one to ask if things are better on MO.
Comment: @EeveeTrainer Thank you for your comment. I've edited the question to be more open and reasonable. Further, I'm not too knowledgable about the zeta function given my high school calculus knowledge. Any information would help me!
Comment: With respect to one particular case ($a=b=1, c=2$), there is a discussion on it in this video - https://www.youtube.com/watch?v=aYc9ManKC-s - I haven't watched it yet so I don't have anything to offer there. Just figured you might find it useful.
Comment: @EeveeTrainer With respect to the video, I can't believe what a coincidence it was with my question, to be posted on the same day!
Comment: @clathratus that is for the alternating sum of $I(2,1,2)$
Answer: $I(a,b,c)
=\sum_{n=0}^\infty \frac{1}{(an+b)^c}
$
Some simple cases.
$I(1,1,c)
=\sum_{n=0}^\infty \frac{1}{(n+1)^c}
=\sum_{n=1}^\infty \frac{1}{n^c}
=\zeta(c)
$
$I(2,2,c)
=\sum_{n=0}^\infty \frac{1}{(2n+2)^c}
=2^{-c}\sum_{n=1}^\infty \frac{1}{n^c}
=2^{-c}\zeta(c)
$
$\begin{array}\\
I(2,1,c)
&=\sum_{n=0}^\infty \frac{1}{(2n+1)^c}\\
&=\sum_{n=0}^\infty \frac{1}{(2n+1)^c}+\sum_{n=0}^\infty \frac{1}{(2n+2)^c}-\sum_{n=0}^\infty \frac{1}{(2n+2)^c}\\
&=\sum_{n=1}^\infty \frac{1}{n^c}-I(2, 2, c)\\
&=I(1, 1, c)-I(2, 2, c)\\
&=\zeta(c)-2^{-c}\zeta(c)\\
&=(1-2^{-c})\zeta(c)\\
\end{array}
$
If $b$ is an integer,
$I(1,b,c)
=\sum_{n=0}^\infty \frac{1}{(n+b)^c}
=\sum_{n=b}^\infty \frac{1}{n^c}
=\sum_{n=1}^\infty \frac{1}{n^c}-\sum_{n=1}^{b-1} \frac{1}{n^c}
=\zeta(c)-\sum_{n=1}^{b-1} \frac{1}{n^c}
$
Note that
$I(a,b,c)
=\sum_{n=0}^\infty \frac{1}{(an+b)^c}
=a^{-c}\sum_{n=0}^\infty \frac{1}{(n+b/a)^c}
=a^{-c}\zeta(c, b/a)
$
the Hurwitz zeta function.
See https://en.wikipedia.org/wiki/Hurwitz_zeta_function
for a discussion of this.
Comment: Thanks for your answer! This was exactly what I was looking for when I first thought of the question. I can't wait to study this function more.
Comment: See my addition at the end of my answer.
Answer: While not a complete answer, if $c$ is a positive integer greater than 1 the sum can be written in terms of the polygamma function $\psi^{(m)}(z)$.
From the series representation for the polygamma function, namely
$$\psi^{(m)}(z) = (-1)^{m + 1} \Gamma (m + 1) \sum_{n = 0}^\infty \frac{1}{(n + z)^{m + 1}}, \quad m > 0, z \notin 0,\mathbb{Z}^-$$
if we rewrite your sum as
$$I(a,b,c) = \frac{1}{a^c} \sum_{n = 0}^\infty \frac{1}{(n + b/a)^{(c - 1) + 1}},$$
in terms of the polygamma function the sum becomes
$$I(a,b,c) = \frac{(-1)^c}{a^c \Gamma (c)} \psi^{(c - 1)} \left (\frac{b}{a} \right ).$$
Here $c > 1$ where $c \in \mathbb{N}$, $a > 0$, and $b \neq 0,-a,-2a,\ldots$
Answer: For $a=b=c=k$, where k is a constant, it seems as though $I(k, k, k) = \frac{\zeta(k)}{k^k}$


Installed new SSD on Macbook Air now won't let me reinstall OS

Question: I have a 2012 Macbook Air. It shipped with 64GB SSD but I upgraded it to 240GB using a 3rd party manufacturer. I was planning on doing a clean install on the system but when I checked to make sure if I could download it, the installer failed to verify that I could install it on the machine. It is like the installer isn't recognising it as a Mac. Any advice?
Comment: You should be able to install from a USB drive if nothing else. http://osxdaily.com/2012/02/17/make-bootable-os-x-10-8-mountain-lion-usb-install-drive/
Comment: What was the exact error?
Answer: OK so ultimately I was able to solve the problem and here is how.
I noticed that when tried to install OSX straight away it failed but when I selected a drive that had OSX installed on it, it validated successfully. However once I had erased the drive it no longer contained a copy hence validation failed. I still had my old SSD which contained a full copy so when I plugged that in via USB and selected it in startup disk, the installer validated it and allowed me to install OSX on the new drive.
Answer: Is your Macbook Air as a registered purchase on the Mac Server, I use to have this problem, then I registered by entering a valid date of buying, which it asked me for (a copy of the bill is required to do so). Now I can Install the Updates, Check by putting your Serial number here Apple warranty check


Factor graph vs Factor graphical model

Question: In inference we use the terms undirected graphical models and directed graphical models. Why do we say factor graph instead of factor graphical models?
Answer: You say factor graph when referring to the graph.  When referring to the model, you could indeed say factor graphical model.  That Wikipedia page contradicts itself by saying that a factor graph is both a graph and a model.
Comment: It seems to be the norm in the inference field to talk about "Factor graph". Googling "Factor graphical model" yields only 20 results...
Answer: First you need to know the definition of probability graphical model (PGM).

Given a graph G, a distribution p.
a PGM is a pair (G,p), where p factorizes over G.[^1]

The keypoint is where G is a graph , not a factor graph.
Well ,I think there is nothing wrong to say factor graphical model (factor graph G, a distribution p), though there's no such use in literature, because factor graph has redundant information for this definition.
The graph's main advantage to representation is I-map property (i.e. conditional independence ). Even so, it is not very fined-grained representation. That's why factor graph or other representations comes in. (e.g. many factor graphs may represent the same Markov Network [^2] )
In UGM case, we usually have three representation : Markov Network, Factor Graph, Log-linear Model. The latter is finer-grained than previous one.[^3]

Why inference use factor graph? My opinion is

it can represent directed and undirected graphical model. Many inferences are agnostic to both models.
it can reveal more finer structure than Markov Network that help the message passing algorithm. [^4] Though I am not very familiar to Belief propagation ,I guess it may like reveal tree structure that is ambiguity (to a clique) in Markov Network.

[^1]: Kollar & Friedman 2009 (definition 3.5)
[^2]: Murphy 2012 (Figure 22.2)
[^3]: Kollar & Friedman 2009 (4.4)
[^4]: Murphy 2012 (22.214.171.124)
reference:
Kollar & Friedman 2009. Probabilistic Graphical Model.
Murphy 2012. Machine Learning, a probabilistic perspective.

Factor graph vs Factor graphical model


Use conditional formatting to add text

Question: Is it possible to use conditional formatting to edit/add text in a cell? E.g., if it matches the custom formula "=B9>A9", add "is greater than A9" as text at end of whatever is in B9. I didn't find any method to add custom formatting, all I'm seeing are colour/font formatting options.
Answer: Conditional formatting can only be used to change text and/or background formatting.
See: Google Support: Use conditional formatting rules in Google Sheets
Answer: While in Excel is possible to use Conditional Formatting to apply conditional numbering formatting including custom text, in Google Sheets is not possible at this time, so a script is needed. To learn the basics of Google Apps Script see https://developers.google.com/apps-script/overview.
The following code adds is greater than A9 to the value of B9 and only to the value of B9 whenever the value of B9 is modified and it's greater than the value of A9:
function onEdit(e) {
  var range = SpreadsheetApp.getActiveRange();
  var value = range.getValue();
  var reference = range.getA1Notation();
  if (reference == 'B9') {
    var A9 = SpreadsheetApp.getActiveSheet().getRange('A9').getValue();
    if (typeof value == 'number' && value > A9) {
      range.setValue(value + ' is greater than A9');
    }
  }
}

Answer: You would have to use AppsSCript I'm pretty sure. as Long as you have predictable data entering the data you can move it around and do just about anything.
if you've never used AppsScript you can open the script editor under the Tools> Script editor selection. I recently just did a little snippet to take the value entered in 6 digit format and use that to change the backround and font color the coresponding color in Hex. Maybe this will help, I'm only a begginer myself. Cheers. I made a beginers Tutorial Here that may help.
       function onedit() {
      var ss = SpreadsheetApp.getActiveSpreadsheet();
      var s = ss.getActiveSheet();
      var r = s.getActiveRange();
      var row = r.getRow();
      var hex = r.getValue();
      if(row>20){
      r.setBackground('#'+hex).setFontColor('#'+ hex);
      }
    {
// EDIT: this code is for generating urls for prefilled google forms.
// it also changes content of cells depending on a few variables
// it is triggered via OnEdit() in AppsScript on a Google Sheet

function SampleFormUrl(U){
  var colIndexU = U.range.getColumn();
  var rowIndexU = U.range.getRow();
  var daysSince = s.getRange(rowIndexU,25);
  if( U.value == "Arrived" && colIndexU == sampleCol ){
    daysSince.clear();
  }else
  {  if( U.value == "Send" && colIndexU == sampleCol ){
    var formlinkCell = s.getRange(rowIndexU,26);
    var forminfo = s.getRange(rowIndexU,5,1,7);
    var formSheet = ss.getSheetByName("Data");
    var formInput = formSheet.getRange(11,2,1,9);
    forminfo.copyValuesToRange(formSheet, 2, 9, 12, 12);
    var formUrlRange = formSheet.getRange(6,1);
    var formUrlCell = formUrlRange.getCell(1,1).getValue();
    formlinkCell.setValue(formUrlCell);
    U.range.setValue("Sent");
    daysSince.setValue(0);
  }
}
}

Comment: You are right regarding that a script is required but the question is about adding changing the value of a cell when a condition is met.

Use conditional formatting to add text


migration of code from SP2007 to SP2010

Question: I have a small project based on SP2007, I have to re-built it on SP2010 as a sandbox solution. How we can start and do it. Can anyone provide me and link documents where each steps are mentioned in details.
Comment: If you do not have fancy dll references in your project you  can install a SP2007 solution on a SP2010 server.
Answer: Creating a SP2010 Sandbox solution in Visual Studio will be almost the same (and even easier) as with your previous SP2007 (farm) solution. Tip: use Visual Studio 2012 it contains a lot of new functionality and makes SharePoint development a lot less frustrating.
Keep in mind that there are some (security) restrictions when developing a sandbox solution. It might be possible that you can not port all functionality to a sandbox solution.
Starting from SP2013, using .NET code in sandbox solution is not officially supported anymore (although it still seems to work). So for simplicity sake I would not convert your current SP2007 (farm) solution to a sandbox solution but I would simply update it to a SP2010 (farm) solution. You can do the same process later when migrating to SP2013 (on-premise).
Answer: These links could be beneficial:

http://social.technet.microsoft.com/Forums/office/en-US/de6e05e3-bef1-4294-949a-30478fb29a9e/migrate-a-solution-sharepoint-2007-2010?forum=sharepointadminprevious
Migrating a solution from 2007 to 2010
http://geekswithblogs.net/juanlarios/archive/2011/03/29/upgrading-sharepoint-2007-projects-to-sharepoint-2010.aspx

Please let me know if you face any issue.

migration of code from SP2007 to SP2010


Why is E major a secondary dominant in the key of C?

Question: I have searched the forum and found answers stating that E Major is a secondary dominant in the key of C because it is the V chord from A Minor. What I don't understand is why the E chord is Major and not Minor. The key of A Minor is simply the relative to C Major, right? So, how is the E Major when neither C Major nor A Minor contain an E Major chord? E Major IS the V in the key of A Major.. but that's a whole different key. So, do we take C and look at its relative Minor(A) then jump to its parallel Major, and take its V chord???
Comment: In addition to the answers that you're receiving, note that in later music, this E-major chord doesn't have to be a secondary dominant in the key of C; plenty of composers playing with third relations would write something like I–III#–V, moving that E major directly to G. But typically E-major chords in C are understood as V/vi.
Comment: @Richard - At that point, those foreign chords that do not resolve like foreign dominant chords would are often **chromatic mediants**, not **secondary dominants**.
Comment: @Dekkadeci Correct! Sorry, using that terminology would have made my comment more clear.
Answer: A secondary dominant means we are using a dominant 7 chord on a different root the V. This of course then implies a resolution into a different chord than the dominant. As secondary dominants require chromatic alteration of course many chords can be reached in this manner. The probably most classic secondary dominant would be the double dominant, that is the dominant of the dominant, i.e. the dom 7 chord on the II. In C major this would then be D dominant 7 (so a D major chord), resolving into a dominant 7 chord on the actual dominant G.
In your case E dominant 7 would either resolve to A minor as scale degree of C major, or it could resolve into an A domiant 7, which could resolve into said double dominant of D. So in fact E major could be seen as the quadruple dominant of C. Both these meaning are useful and not uncommon. The first one kind of relies on the ambiguity between tonic and parallel mediant, while the second one naturally forms a circle-of-fifths sequence.
Comment: @user45266 The "secondary" just means it is not the dominant of the main tonic, but of a secondary tonic. I'm not sure how one is supposed to extend this further, but feel free to get creative :) The *double* dominant on the other hand is the dominant of the dominant, and can thus be extended former.
Comment: if you want to get technical (and who doesn't!), I think the extension of the term "secondary dominant" would probably be something like "tertiary dominant", "quaternary dominant", etc :P
Answer:
So, how is the E Minor when neither C Major nor A Minor contain an E Minor chord?

The key signature of A minor indeed does not include an E major chord.
But harmony in minor keys is not determined merely by the key signature.
When it comes to keys in the major/minor system of harmony both major and minor keys have a leading tone which is one half step below the tonic. In the case of a tonic of A - whether the key is major or minor - the leading tone below tonic A is always a G#.
Now let's get back to that secondary dominant chord. The basic dominant chord is one rooted on the dominant scale degree and whose third is the leading tone. So, the purely diatonic dominant triad for the key signature of A minor is an E minor triad where the chord's third is G natural, but when making a proper dominant chord the leading tone G# is used and the chord is then a major triad.
The big take away from this should be that dominant harmony, the full variety of dominant type chords, is characterized by the leading tone. A major triad rooted on the dominant (which then contains the leading tone), diminished seventh chords rooted on the leading tone, tritone substitutes (which contain the leading tone but not the dominant scale degree), etc. are all types of dominants, because they include the leading tone.

E Major IS the V in the key of A Major.. but that's a whole different key.

...whole different key signature.
The actual difference between A minor and A major is a difference of mode.
A summary of minor key harmony is not appropriate here. You should get a good harmony textbook and read the part about minor key harmony. In short, minor key harmony is more complex that major, uses more chromaticism for basic harmony. In other words the difference between major and minor key isn't wholly different. It is modally different.
Comment: I do have to admit that, despite having the leading tone of the dominant, augmented 6th chords make for pretty poor secondary dominant chords. (E.g. Italian Aug. 6th of C minor = Ab-C-F#, note the F# as the leading tone of G)
Comment: Augmented sixth chord - in their traditional form - are modifications of the subdominant and resolve to a dominant. Sure, the modification of the subdominant is raising the root, so `#^4`, and that looks like a leading tone to the dominant.
Comment: The devil's in the details. Traditionally, augmented sixth chords come from the minor mode. `iv6` has `b^6` in the bass. Root `^4` is above. Raise root to `#^4` to get the alteration of `iv` and it becomes and augmented sixth chord.
Comment: Take the same sonority but put it in a jazz context. Start with a regular dominant seventh chord, root on the dominant. Lower the fifth of the chord. `^2` moves down to `b^2`. That's an alteration of a dominant, `V7b5`. The sonority is the same as an augmented sixth chord. The various intervals of the chord are relatively the same, but the two chords are positioned differently within the key.
Comment: A leading tone is the `^7` scale degree. In an augmented sixth chord progression the leading tone is not in the augmented sixth chord but in the dominant it resolves to. The progression is a half cadence. In a jazz altered dominant `V7b5` the leading tone is in that dominant, but it isn't the altered tone.
Comment: Relative to their positions in the tonality. Augmented sixth chords alter the subdominant `^4` degree and don't contain a leading tone, and jazz `V7b5` alters the supertonic `^2` scale degree and do contain a leading tone.
Comment: The augmented 6th chord crack I made earlier was more a reference to them being at least technically valid tritone substitutions of V7/V, and they similarly contain the leading tone but not the `^5` of the dominant (key) unless they are French Aug. 6th chords. *And* they invariably resolve to actual dominant(-function) chords. Yet (probably) no harmony textbook aimed at classical music will say that augmented 6th chords are secondary dominant chords.
Comment: If "the chord in question" moves to a real `V` chord, I imagine calling it a tritone substitution only if you don't know what an augmented sixth chord is. I have an old print version of _I got Rhythm_, and it uses exactly that, "the chord in question" to a dominant `V` chord, and I immediately recognized it an an _augmented sixth chord_. If the same kind of movement happened resolving to `I`, I would have called it a tritone sub. dominant to tonic. All of this depends on knowing what is `I` and `V`, because then "the chord in question" either does or does not contain the leading tone.
Comment: I'd call "the chord in question" that moves directly to `I` a chromatic mediant instead of an augmented 6th and *definitely* instead of a "tritone sub. dominant to tonic". Admittedly, the closest I recall to seeing that chord progression in the wild is the Cm-Ab7-Cm-Ab7 (i-(b)VI7-i-(b)VI7) movement of the Toad's Factory theme of *Mario Kart Wii*, and its C-F#-C-F# in the melody there actually makes that chord progression sound deceptively like Cm-F#-Cm-F# chords instead.
Answer:
What I don't understand is why the E chord is Major and not Minor.

Dominant chords always have a major third (in classical harmony, or at least in the core era of classical harmony, which is known as the "common practice period").  The dominant chord is built on the fifth scale degree, so it consists of the fifth, seventh, and second degree of the scale.
In the major scale, this gives you a major chord.  (For example in C major it's GBD, G major.)  In the (natural) minor scale, it gives you a minor chord, but the seventh is raised, which makes the chord major.  This raising of the seventh is what led to the invention of the harmonic and melodic minor scales.  For that matter, this raising of the seventh is what led to the convention that dominants are always major.

The key of A Minor is simply the relative to C Major, right? So, how is the E Minor when neither C Major nor A Minor contain an E Minor chord?

What are you talking about?  They both contain an E minor chord!  The chord built on the third scale degree of the major scale, containing the third, fifth, and seventh scale degrees, is a minor chord.  In C major, the third, fifth, and seventh scale degrees are E, G, and B, which is an E minor chord.
The chord built on the fifth scale degree of the (natural) minor scale is also a minor chord (unless it's functioning as the dominant).  In A minor, that's the E minor chord.

E Major IS the V in the key of A Major.. but that's a whole different key.

E major is the V of both A major and A minor, thanks to the convention of raising the third of the dominant chord.
But let me suggest a different way of thinking about secondary dominants.  A secondary dominant is a chord that functions as the dominant to any scale degree other than the root of the key.  It doesn't matter whether the chord built on that root is major or minor -- the secondary dominant always has a major third (and, if it's a seventh chord, it always has a minor seventh, which is how you can differentiate between a major chord that's just part of the key and a major chord that's a secondary dominant).
So, for example, in C major, in addition to E major as a secondary dominant, you could have D major as a secondary dominant (this is the "original" secondary dominant because it's the dominant of the dominant).  Other possible secondary dominants: A major, B major, F♯ major, and even C major -- if you have a C major with a B♭, that is to say, a C dominant seventh chord, it's probably functioning as a secondary dominant to F.
This may all seem very confusing.  It makes more sense in terms of roman numeral analysis.  There, you have these chords in the major scale: I ii iii IV V vi viiº.  Upper case for major, lower case for minor, a degree symbol for diminished.  In C major, the chords of course are C Dm Em F G Am Bdim.  The Roman numerals for E major as the secondary dominant to A major, therefore, is V/vi, read as "five of six."  D major as the dominant of the dominant, similarly, is V/V or "five of five."
Now all this is very firmly oriented toward classical music, especially of the 17th through the 19th centuries.  In jazz and other popular styles (and in more harmonically adventurous 20th-century classical music) it's common to have a chord that has the form of a dominant seventh chord but doesn't have a dominant function.  There are all kinds of chords that don't resolve "properly" according to the classical rules because, well, the extra notes aren't necessarily treated as dissonances that need to resolve.  They're often just there for color and texture.  I mention this because the concept of secondary dominant is also far more useful in classical theory than it is in jazz or popular music.  You're not going to find many D major or E major chords in classical C major pieces that are anything other than secondary dominants.  The same isn't necessarily true of other musical styles.
Comment: I think he meant to write "neither C Major nor A Minor contain an E _Major_ chord..." I didn't even notice until reading your answer.
Comment: @MichaelCurtis that seems very likely; the possibility hadn't occurred to me.
Comment: That's correct.. I edited it. Thanks, for everything!
Answer:
What I don't understand is why the E chord is Major and not Minor.

To create tension.

E Major IS the V in the key of A Major.. but that's a whole different key. So, do we take C and look at its relative Minor(A) then jump to its parallel Major, and take its V chord???

Every major scale has only one dominant chord, the V chord. In the key of C, the dominant chord is G7.
A dominant chord has a strong pull to the I chord which is a fifth below it. In the key of C, G7 has a strong pull to C.
Sometimes, you might want a similar sound with a pull to a chord other than the I chord. In these cases you could a fifth above, and construct a dominant chord from there. Eg. If you wanted to create a strong pull to the Am chord, you could precede it with an E7. Here E7 is a secondary dominant chord.

Here are a few secondary dominants in the key of C:

Note
Diatonic Chord
Secondary Dominant

C
C
n/a

D
Dm
A7

E
Em
B7

F
F
C7

G
G
D7

A
Am
E7
Comment: You seem to hint quite strongly that a secondary dominant chord is there to lead to its own tonic. That's not necessarily the case. And F(7) certainly wont lead at all to Bo.
Comment: @Tim - don't dominant chords—whether secondary or not—always lead to its own tonic? Whether or not we choose to take its lead is a different thing altogether. I agree that F7 does not have a leading tone relationship with Bdim, I will update the answer to make a note.
Comment: Your first two bullet points seem to be saying the same thing, consider merging them.
Comment: No, they don't. There are many pieces where, for instance, key C, there's E>F. Rather than E>A/m.
Answer: A secondary dominant is, as stated, a dominant chord - in its own right. It doesn't actually have to lead straight to its own tonic, although it often does.
Taking your example of E. That's the secondary dominant which could lead to A, or Am. That Am just happens to be relative to C, but that's not particularly relevant.
Other secondary dominants used in key C would be A (to lead to D/Dm), D (to lead to G/Gm) or B (to lead to E/Em). Note that each secondary dominant chord has notes which are chromatic - don't belong in key C. Notably the leading note of the secondary dominant's tonic. Like I said, any secondary dominant may lead to its tonic, but it doesn't have to. I believe there should be a distinct name for those which do, but haven't found one yet.
Comment: Answering your "I believe there should be a distinct name for those which do, but haven't found one yet" - for those that do not resolve like deceptive cadences either, that term is often **chromatic mediant**. This term also applies to chromatic submediants but notably does not apply to chords such as B in C major.
Answer: Key is much more about the center of harmony than about a scale or set of notes. Being "in a key" does not mean "in a scale", it means what the center is.
If a C major chord feels like a "home chord" i.e. center of harmony in the song, then the song is in the key of C major, regardless of what notes and pitches are played.
As an example, in a song that's in C major, you can have a chord Db7, even though that chord requires the center pitch itself to be flatted to Cb. After that, when you play a C major chord, the C note is restored back to C natural. Such "chromatic alterations" to note pitches are denoted with accidentals in Western musical notation.
The key signature specifies a default, often-used set of pitches that's useful in songs in that key, if the song follows certain traditions and conventions of Western music. If the song diverts too far away from conventions of certain Western music for which the key signature system was developed, then it may be better to not use key signatures at all, but add an accidental to each and every note. This is sometimes done to e.g. transciprions of jazz improvisations which have an ambiguous key, or just wander around in different keys very quickly.
When you have an E major chord in the key of C, you have to sharpen the G note to get a G#. In musical notation, this is denoted by writing a sharp accidental next to the note in question.
Even if there are whatever sharps and flats, your song is in the key of C, if you feel that C major is a home chord. Claiming that a song or passage is in such-and-such key, is a statement from the person saying that, about what he or she considers the center of harmony to be. It is not a statement about pitches that are allowed to occur during the song or passage.
Answer: First,  'dominants', secondary or otherwise, are major chords.   The major 3rd of the chord acts as the leading note of whatever it's the dominant of.
Second, A minor is not restricted to the notes of the natural minor scale.   There's also the 'harmonic minor' scale, with a sharpened seventh note.   In A minor, this will be G♯.   So we can have that E major chord and still be strictly diatonic!
(Not that there's any requirement to be strictly diatonic.  We can have chromatic notes/chords and still be 'in C major' or 'in A minor.)


level of control of the os on the phone hardware

Question: I am new to Android and mobile phones development. I want to develop an application that needs to have a total control over the "phone" of the smartphone, i.e. controlling all the communication of the GSM chip with the cellular system, accessing the SIM card identity that it sends (encrypted) to the cellular system, disabling the cellular antenna and resuming it back, and more of that kind...
Can it be done with Android? Does the software (OS) have control over all of the phone components in a smartphone, or there are some parts that are done in the hardware level only? (I guess that the Android API won't enable me to do everything i want, but even theoretically is it possible if I recompile the OS after making the changes there?)
Thanks!
Answer:
but even theoretically is it possible
  if I recompile the OS

Yes everything is possible with custom firmware.


Get DEM from Google Earth Engine

Question: How can I get ASTER or SRTM DEM for years like 2016, 2020,... in Google Earth Engine? I can't filter date for SRTM DEM in GEE. It seems that SRTM DEM doesn't have multi-year data, it was captured only in 2000 and available in GEE. So what about ASTER DEM? Can I get it for the year like 2020? How can I filter date for it in GEE? (I can filter ImageCollection like Landsat but for images like DEM I can't filter date.)
Answer: Unfortunately, ASTER dem is not a temporal dataset, meaning it also has a set temporal resolution. These dems are created using imagery spanning a long time. The latest version of aster dem (ASTGTM) used imagery from March of 2000 to November of 2013 and it combined all the data, meaning that you can't split it by filtering in GEE
Comment: If you are looking at urban change detection I would suggest using optical satellite imagery such as Sentinel-2 or Landsat 8 instead of elevation data. SRTM is also constant in time, so you won't have a lot of temporal data to choose from.
Comment: Thank you so much, so how about SRTM???? totally i need dem (ASTER or SRTM) for my field "urban change detection for 20 years" so I downloaded Aster digital elevation model V003 from earthdata.nasa.gov for the years like 2014، 2017، 2020 and I should make mosaic (in arcgis) and merge images but it doesn't merge well(merge with black margin). so i wanted to try it in gee.

Get DEM from Google Earth Engine


Ultra low noise +/-15V power supply

Question: I'm designing a preaplifier for a geophone. The amplifier uses OPAMPs which require +/-15V power supply for optimal operation. How can I generate such voltage rails without inserting excesive noise into circuit? Power supply should be as quiet as possible, with 9V unregulated input. The signals from the microphone are very weak.
Comment: This is sadly not a proper requirement doc: "Quiet as possible": Well, then get a giant solar cell, cool it as far as you possibly can, and expose it to a perfectly regulated light source. Or, you could actually try to figure out how much noise your system inherently has, thus setting a lower limit for what your power supply needs to fulfill :) Then, you'd actually have anything to work with instead of us just giving you answers that are either waaaay over the top or insufficient.
Comment: Use different op-amps that run on 9 volts.
Comment: Batteries are pretty good low noise sources.  Use four 9V cells to make two 18V rails, then drop to 15V with linear (not switching) regulators.
Comment: Filter, filter, filter.
Comment: What is common-mode range of your op amps ? I'm curious about that.
Comment: What current do you need?
Comment: Another approach is using boost converter and a precedent LDO + filter stage.
Comment: To rephrase @IgnacioVazquez-Abrams: Battery, Battery, Battery.
Comment: Assuming 100dB PSRR at DC--1,000Hz, and a total integrated noise of 0.5 nanoVolt RMS over DC--10Hz, the noise density is 0.5nV/sqrt(10) = 0.5nV/3.16 = 0.15nV referred to input, after the 100db PSRR. The equivalent VDD noise is 0.15nV * 100,000 = 15 microVolts/rootHertz. This is not particularly quiet.
Answer: Use a linear power supply with a screened power transformer, good filtering, followed by linear low-noise regulators (eg. TI) followed by a bit of RC+ ferrite bead filtering. Or batteries + linear regulators etc.
If you really need to work from a 9VDC battery you would be better off redesigning the circuit to work from something like +/-2.5V than trying to insert a switching regulator and then cover up the noise. It's not impossible to do it as you suggest, it just requires a lot of care, to the point where most experienced consultants (ie. folks who have an idea of what's involved) are going to no-bid or greatly increase the cost to cover all the work. Geophones are some of the most demanding signal sources around, and if you want to get low nV/sqrt(Hz) noise spectral density down to fractions of a Hz a lot of care is required.
Your signal bandwidth will probably be < 10Hz but you do need to worry about higher frequencies, including RF, causing subtle low frequency noise through nonlinear behavior.
Answer: The LT1763 and LT1962 are very low noise parts ~20uV-rms and have a higher PSRR than that of other companies at 65dB, which will give you better noise rejection if operating from a noisy source. The source 500mA and 300mA respectively.
If you need more current it is possible to parallel them (which will also give you lower noise due to the averaging of noise sources).
They are in a SOIC8 package which is easy to prototype with.
If you want to move to an SMT device the LT3045 and LT3042 are lower noise at 0.8uV-rms and have a kelvin connection to reduce source resistance and other noise sources.

Ultra low noise +/-15V power supply


I need an address matching algorithm

Question: I have looked around online for this but haven't found much really. Basically I need to compare a bunch of addresses to see if they match. The addresses could be written in all different ways. For Example : 1345 135th st NE, 1345 NE 135TH ST, etc. Plus they could be in different languages as well. Before I attempt to write some parsing matching algorithm on my own does anyone know any libraries or ways I could easily do this? My friend though of using google or bing maps web service and passing them the address and getting back the geo-coordinates and comparing using the coordinates instead of string matching. But then I have to call a web service thousands of times for all these addresses I have, not very elegant ;) Any help would be nice :)
Answer: I don't think that this is a REGEX type of problem. You are looking at converting to a comparable format first.
There are several web services / products available that will standardize an address for you. Bing for "USPS Address Standardization API" and you will find a ton of information. Once the address is standardized, the comparison should be straightforward.
http://www.bing.com/search?q=usps+address+standardization+api&go=&form=QBRE&qs=n&sk=&sc=1-32
Alternatively you can GeoCode the address to get a set of coordinates and then compare those.
http://code.google.com/apis/maps/documentation/geocoding/
Comment: The google code also allows you to return a "properly formatted address" but I think after so many API calls you gotta pay or something.
Answer: US addresses can (usually) be uniquely represented by a 12-digit number called the delivery point (DPBC). This number consists of the full 9-digit ZIP Code and a 3 digit delivery point number.  This is what is used to form barcodes on mail pieces to speed up delivery. Using a service that is CASS-Certified can provide the 12-digit delivery point and even flag duplicates for you.
In the interest of full disclosure I work for SmartyStreets, which was formerly Qualified Address, which was mentioned in the other answer by Mowgli.
We provide an API that can be queried as well as a batch processing service (which will flag duplicates as explained above).
Keep in mind that even the 12-digit DPBC doesn't always uniquely identify a particular address. This happens frequently when a particular street block, or 9-digit ZIP code, has a long stretch of homes that have similar primary numbers. In these cases, it's best to use a CASS service to standardize and validate the addresses, then hash them for convenient comparisons. (But as said, duplicates will already be flagged by some CASS services.)
Update: SmartyStreets now provides international address verification.
Comment: No, just having the ZIP+4 code (9-digits) doesn't go far enough.  There could be secondary information (apartment numbers, descriptors, etc..) that are only found in the 12-digit Delivery Point barcode (consisting of the 9-digit ZIP Code plus the delivery point and a check-digit).  (This is specific, of course, to US addresses)
Comment: Assigning the zip plus 5 code will likely be the best way to subsequently compare.  Assigning the code requires matching and lookup into the full address database.
Answer: I found 2 options.
Firstly, maybe, instead of taking any input, you let the users choose from a limited number of options, similar to how facebook deals with addresses. If you use an autocomplete api, as they type, the possible addresses will be narrowed down by the api. Here is one from google:
http://code.google.com/p/geo-autocomplete/
Secondly, address finding & qualifying (but they arn't free):
https://www.craftyclicks.co.uk/
https://smartystreets.com/ (Previously Qualified Address)
https://www.alliescomputing.com/ (Previously offered World Addresses)
Answer: I wouldn't consider this a regex problem.
One free tool that could be helpful is usaddress, a python library for parsing addresses. It performs pretty well on all sorts of address formats, b/c it uses a probabilistic approach rather than a regex approach (although it is made for US addresses, & may not work well on addresses in other languages)
http://usaddress.readthedocs.org/en/latest/
Parsing addresses won't solve your problem 100%, but comparing two addresses, especially addresses w/ varying formats, will be much easier if the addresses are split into their respective components (so that you can compare street # against street #, city against city, etc)
Then, to compare records, you can use dedupe - another free python library.
http://dedupe.readthedocs.org/en/latest/
Answer: There is an open source python library for record deduplication / entity resolution that can be applied to address matching: Dedupe.
It's free and can be run on a laptop, as opposed to a huge server.
Answer: This requires intelligence to do correctly; computers aren't intelligent.
A simple algorithm could tell you which addresses have something in common, for example, "1345 135th st NE" and "1345 NE 135TH ST" have the number "1345" in common.
You would then have fewer to compare yourself. It would also reduce the number you geolocate.
Answer: This is definitely not a REGEX problem. This is 2018 and we have hands on more advanced methods yet. Both R and python offer solutions for that type of problem
In R: https://cran.r-project.org/web/packages/RecordLinkage/index.html
In python: https://recordlinkage.readthedocs.io/en/latest/about.html
Answer: 1. Using address string similarity
Bacause of addresses could be written in many different ways it's usful to apply fuzzy logic and calculate similarity of address strings. I used to solve this task a fuzzywuzzy Python library. It has a functions that calculate Levenshtein Distance as a differences between strings.
from fuzzywuzzy import fuzz

addr1 = "USA AZ 850020 Phoenix Green Garden street, 283"
addr2 = "850020, USA AZ Phoenix Green Garden, 283, 3a"
addr3 = "Canada VC 9830 Vancouver Dark Ocean street, 283"

addr_similarity12 = fuzz.token_set_ratio(addr1, addr2)
addr_similarity13 = fuzz.token_set_ratio(addr1, addr3)

print(f"Address similarity 1 <-> 2: {addr_similarity12}")
print(f"Address similarity 1 <-> 3: {addr_similarity13}")

Output will be:
Address similarity 1 <-> 2: 96
Address similarity 1 <-> 3: 55

Really, first two addresses is almost the same and last two ones are different. Important task is a choosing appropriate threshold that will indicate address equality.
2. Using Google Map Geocoding API
Geocoding is the process of converting addresses (like "1600 Amphitheatre Parkway, Mountain View, CA") into geographic coordinates (like latitude 37.423021 and longitude -122.083739). And then it's possible to calculate numerical "distance" between two addresses.
Comment: Thank you for mentioning the "Levenshtein Distance" algorithm. Googling that has opened up a whole new world of "string metric" algorithms that are useful for this problem. I think  using a service like Google GeoCoder or Google's maps API is by far the most expensive way to solve this problem and having been down that path, Google is NOT as accurate as you'd expect forcing you to perform many secondary checks to verify results.
Answer: Well one way to solve this problem is to convert both the addresses in same format. One easy way to do this but using Google Map Geocoding API is to simply pass both addresses to the API and get the output. The output for Geocoding API looks something like:
FORMAT OF GOOGLE'S GEODIRECTORY API (for reference):
    {'results': [{'address_components': [{'long_name': '22',
         'short_name': '22',
         'types': ['street_number']},
        {'long_name': 'Rue de Berri',
         'short_name': 'Rue de Berri',
         'types': ['route']},
        {'long_name': 'Paris',
         'short_name': 'Paris',
         'types': ['locality', 'political']},
        {'long_name': 'Département de Paris',
         'short_name': 'Département de Paris',
         'types': ['administrative_area_level_2', 'political']},
        {'long_name': 'Île-de-France',
         'short_name': 'IDF',
         'types': ['administrative_area_level_1', 'political']},
        {'long_name': 'France',
         'short_name': 'FR',
         'types': ['country', 'political']},
        {'long_name': '75008', 'short_name': '75008', 'types': ['postal_code']}],
       'formatted_address': '22 Rue de Berri, 75008 Paris, France',
       'geometry': {'location': {'lat': 48.8728822, 'lng': 2.3054154},
        'location_type': 'ROOFTOP',
        'viewport': {'northeast': {'lat': 48.8743208802915,
          'lng': 2.306719730291501},
         'southwest': {'lat': 48.8716229197085, 'lng': 2.304021769708497}}},
       'place_id': 'ChIJWxDbRsFv5kcRRcfu62JSRog',
       'plus_code': {'compound_code': 'V8F4+55 Paris, France',
        'global_code': '8FW4V8F4+55'},
       'types': ['establishment', 'lodging', 'point_of_interest']}],
     'status': 'OK'}

Here notice how google has provided you the different components of addresses like street number, locality etc. Now you can do a weighted/fuzzy matching between these components. Its upto you whether you want all to match or maybe some rules like street number or numbers shoulds always match, for other its okay if 4 out of 5 matches. Also you can consider distance between coordinate (Note : Use Haversine function and not just Euclidean Reference : https://towardsdatascience.com/calculating-distance-between-two-geolocations-in-python-26ad3afe287b ). You can then have a weighted score which should be greater than threshold for them to be consider same place.

I need an address matching algorithm


XY coordinate data not lining up with other layers

Question: When I add XY (lat,long) data to the map in the same PCS and GCS as the other layers, the points are added to the map but do not line up with the other layers. I am using GCS: GCS_North_American_1983, and PCS: NAD_1983_UTM_Zone_16N. When I change the XY data to WGS_1984, the points appear on the other layers. However, I am unable to run any measuring tool. I am trying to use the Near tool to measure distance between the XY data and a polygon layer. This does not work, probably because they are in different coordinate systems. I've also tried converted the XY data into a shapefile and that doesn't work either.
Comment: I am using ArcGIS  10.3.1
Comment: Not the right duplicate!! She set the layer's coordinate system correctly to WGS84 but then can't use the Near tool. Try using the geodesic option on the tool and/or set the data frame to use UTM, and save out the xy data as a shapefile using the DF's coordinate system.
Answer: The input dataset's coordinate system controls what will be used in the Near tool. If the WGS84 points are the input dataset, try setting the distance option to geodesic, rather than planar.
If you'd prefer to use UTM or the planar option, you'll need to reproject the xy data to UTM or another projected coordinate reference system. One way to do this is to set the data frame's coordinate system to what you want the data to use. Add the xy data as normal, setting its current coordinate system (a geographic coordinate reference system). Once it's added, right-click the layer and select data, export data. In the dialog select "use the data frame's coordinate system" option and save the data as a shapefile or a geodatabase feature class. Then use it in the Near tool.
Answer: check SRC on metadata (or prj archive), maybe you are define a proyection, with another SRC.
Or, when you created a new layer, must desactive fly proyection, and work only with the layer that you need.


Installing libboost-python-dev for python3 without installing python2.7

Question: I am trying to install boost bindings for python3 on Ubuntu Xenial, but it pulls in whole python2.7 dependency tree. I do not want or need python2.7 on my system (Docker image). Is there a way to install only python3 bindings?
Answer: I have resolved to compiling and installing boost myself (I also installed/compiled Python 3.6 myself.). I have in my Dockerfile now:
# We have to compile it ourselves against the custom Python and cannot use Debian package.
# Includes a symlink workaround for: https://svn.boost.org/trac10/ticket/11120
RUN cd /usr/src && \
 wget --no-verbose https://dl.bintray.com/boostorg/release/1.65.1/source/boost_1_65_1.tar.gz && \
 tar xzf boost_1_65_1.tar.gz && \
 cd boost_1_65_1 && \
 ln -s /usr/local/include/python3.6m /usr/local/include/python3.6 && \
 ./bootstrap.sh --with-python=$(which python3) && \
 ./b2 install && \
 rm /usr/local/include/python3.6 && \
 ldconfig && \
 cd / && rm -rf /usr/src/*

Answer: You have three options:
1. Build Boost.Python yourself
This is the option I recommend: it's clean, there's no risk to mess up your system and you have full control on what you get. Moreover1

Boost.Python is a separately-compiled (as opposed to header-only) library

so you can just build that. Download the archive and follow the instruction on the Getting Started guide. (This is what OP did.)

2. Use dpkg to avoid installing unwanted dependecies
If you don't want to build Boost.Python yourself, you can bypass apt (and its dependencies cheking) with dpkg.
Let's say you want to install a package named foo which depends on bar and baz, but you don't actually need baz.
apt download foo bar
sudo dpkg --ignore-depends=baz --install foo.deb bar.deb

Notice that apt will still complain about unresolved dependencies (but hey, that's its job), so the problem is not entirely solved: you just swept it under the carpet.
This option is quicker than the previous one, but I wouldn't recommend it.

3. Use equivs to fool apt
This is new to me. Apparently, you can create dummy packages to fulfill the dependencies.
In this way, you don't have to install unwanted/unnecessary packages and apt will not complain about it.
As I said, I've never used equivs before, but you can find out more about it here.
Comment: instead of conveniently using `foo` and `bar` please solve the problem at hand using libboost and whatnot, because your 2nd solution doesn't help. Too generic to be applicable.
Answer: due to my research, it's not possible
libboost-python-dev package has libboost-python1.67-dev dependency.
https://packages.debian.org/sid/libboost-python-dev
and libboost-python1.67-dev has python-dev dependency which uses python 2
https://packages.debian.org/sid/libboost-python1.67-dev
so you cannot do this I think you cannot do this in Debian.
I recommend checking arch base and rpm base distros.
Comment: On Ubuntu 20.04 it only uses Python 3 https://packages.ubuntu.com/focal/libboost-python1.71-dev
Answer: I can offer two solutions, one is to build a Python:3.6 image from scratch. Here python3.x becomes the de-facto choice.
Also, another option which worked for me (in Mac OSX) was:
brew install boost-python --with-python3 --without-python
Comment: Homebrew on Ubuntu??
Comment: https://docs.brew.sh/Homebrew-on-Linux


Prove that, the map $x\mapsto=[x]\cos^2{\pi x}$ is discontinuous at every integer points.

Question: I think that the map $x\mapsto=[x]\cos^2{\pi x}$ may have jump discontinuities at every integer point. However I cannot establish that fact in a rigorous manner.
Can anybody assist me to find the proper way to solve my question?
Thanks for assistance in advance.
Comment: @Shaun, I'll try to remember your words, sorry for the inconveniences caused to all of you. I'm a beginner, I'm new in this portal, that's my fault. But don't understand why people giving vote down to my post, they should remember they were also being a student once upon a time, they should encourage new leaners instead of giving down vote. Thank you,
Comment: @ArnabRoy, it is really unexpected to see people are giving vote down to a new learner, beginner. Everybody should remember their past and should keep in mind that it's one's duty to guide new joiners in a proper way. But Arnab, I am advising you to ask more contextual problems here. Give a proper description of the problem. You are a beginner, hope you will be a good Mathematics lover in the future.
Answer: Let, $c\in\Bbb{Z}$
Let, $g:\Bbb{R}\to\Bbb{R}$ is defined by $g(x)=[x]\cos^2{\pi x}\quad\forall x\in\Bbb{R}$
I'll prove that $g$ has jump discontinuity at $c$.
Note that, $g(c)=[c]\cos^2{\pi c}=c$
My claim is $\lim\limits_{x\to c-} g(x)=c-1$
Choose $\varepsilon>0$
As the map $x\mapsto\cos^2{\pi x}$   is continuous on the whone real line(Why?), we have $\lim\limits_{x\to c+} \cos^2{\pi x}=\lim\limits_{x\to c-} \cos^2{\pi x}=\cos^2{\pi c}=1$.
Now using $\lim\limits_{x\to c-} \cos^2{\pi x}=1$, for $\frac{\varepsilon}{|c-1|}>0$, we can have $\delta_\varepsilon>0$ such that
$|\cos^2{\pi x}-1|<\frac{\varepsilon}{|c-1|}\quad\forall x\in(c-\delta_\varepsilon, c)$
$\implies|(c-1)\cos^2{\pi x}-(c-1)|<\varepsilon\quad\forall x\in(c-\delta_\varepsilon, c)$
$\implies|[x]\cos^2{\pi x}-(c-1)|<\varepsilon\quad\forall x\in(c-\delta_\varepsilon, c)$ (because $x\in(c-\delta_\varepsilon, c)\implies[x]=c-1$)
$\implies|g(x)-(c-1)|<\varepsilon\quad\forall x\in(c-\delta_\varepsilon, c)$
Therefore, for any $\epsilon>0,\exists\delta_\varepsilon>0$ such that $|g(x)-(c-1)|<\varepsilon\quad\forall x\in(c-\delta_\varepsilon, c)$
$\implies\lim\limits_{x\to c-} g(x)=c-1\ne c=g(c)$
$\implies g$ has (left)jump discontinuities at every integer points on $\Bbb{R}$.


Does the fullness of a pressure cooker effect it's performance?

Question: We make stock in our pressure cooker and it ends up being quite full. Will this affect the cooking in some way? Will a pressure cooker that is only 1/3 full cook things differently than if it was 2/3s full? Does it depend on what is being cooked? Naturally it will take longer to come up to pressure the more full it is, but besides that will anything else be different?
Comment: I suspect that this depends on the type of type of mechanism.  The ones that constantly jiggle releasing air I assume going to be more consistent if they have a larger volume of air to leak out.   Newer cookers will lock at a given pressure, so they're not constantly losing air, so might not be affected.  (Unless they get gummed up, as mentioned below).  Also beware of things that swell as you cook them.
Answer: No difference...however, the risk of overfilling is that something clogs one of the safety mechanisms.  My Kuhn Rikon stove top pressure cooker has a max fill line (which I do slightly exceed from time to time) at about the 2/3 mark.


Story about an insurance adjuster from outer space

Question: This story that I read maybe 15-20 years ago (and was definitely published during this period) was told in 1st person point of view and the protagonist was an insurance adjuster. The story took place in outer space (he was working on a ship) and he got involved in an intergalactic conspiracy. It was slightly comical at times (similar to Douglas Adams' work), but for the most part the story was serious in tone. At one point, they visited a planet whose populace was entirely under the influence of a psychotropic drug that caused random hallucinations. Can anyone help me find the name of this story?
Comment: It was a long novel. I'm fairly certain it was written in English, but it could have been French also - when you know a lot of languages they all sometimes blend together :)
Comment: Short story? Novel? Something in between?  Written in English or another language?
Comment: "Bartleby's Planet"?
Answer: Donald Westlake wrote the adventures of an underwriter from Lairds of Luna and his difficulties involved in insurance on other worlds, but I'm not sure that a novel was part of them, not even a fix-up.
The short story was found in The Curious Facts Preceding My Execution and Other Fictions

Murder in Outer Space: Originally called The Risk Profession–from 1961.  The only science fiction story in this bunch, but also a murder mystery.  It's interesting that he liked it well enough to include it–this well after he'd publicly renounced the genre (though he never did stop writing SF entirely).  Me myself, I never thought much of it.  It's all ideas, no characters.  The protagonist is a clever enough fellow, a company man with an independent streak.  He's a futuristic insurance claims adjuster, investigating the suspicious death of an asteroid miner.   He cracks the case, and ends up profiting mightily by it, and I'd rather just move on to the next story, if you don't mind.   Maybe I'll revisit it when I get to Westlake's SF anthology.   And maybe not.
Comment: The Westlake story first appeared in 1961. It's been anthologized at least three times (all in collections of Westlake's short fiction). It's quite focused on the murder mystery angle, and there's no planet where everyone is under the influence of drugs. Possible somebody read it, and picked up where Westlake left off (wouldn't be the first or last instance of that happening). Westlake only wrote one SF novel, *Anarchaos*, which takes place entirely on one dystopian world, and the insurance business is not invoked there (no company would insure anyone or anything on *that* planet).


Ancient Egyptian Mathematicians

Question: Greek and Muslim Egyptian mathematicians are well known throughout the world. But the only Ancient Egyptian mathematician I know of is Ahmes, who said he's just a scribe. Who were the greatest Egyptian mathematicians of Ancient times?
Comment: At the time "scribe" was like a wizard. He could read and write, he used scrolls for that, and it happened in very direct relation with social power. It was much more than someone like a secretary today. Beside that, that he also could calculate, how many big boulders are needed into the next pyramide, there was not so much difference.
Answer: We don't know. The documents we have concerning Egyptian and Babylonian Mathematics do not contain the names of their creators.
Answer:
"But the only Ancient Egyptian mathematician I know of is Ahmes, who said he's just a scribe."

Because in Ancient Egypt math was just a tool to solve real problems (ex: inheritance, accounting, inventory control, ...). Although math was highly developed there compared to other civilizations, there were no mathematician as a profession neither as a thinker.
What existed there was some kind of training in math. Which can be seen in the only two original sources of math info about the Ancient Egypt:

Moscow Mathematical Papyrus
Rhind Mathematical Papyrus

Both are likely math exercises to train future scribes. Ahmes (btw, a common name in Egypt) just transcribed such math exercises from an older and lost source. And, based on the solutions of such exercises, it is possible to infer that there were no concept of mathematical proof at that time. As long as the answer was correct, it doesn't matter what steps were taken.
AFAIK, it required 1500 years for this mindset to change. The Ancient Greeks were actually the first ones to embrace logic and develop rigorous mathematical proofs. Thus allowing the emergence of the first mathematicians (ex: Thales of Miletus).

Ancient Egyptian Mathematicians


How much XP does it take to get to level 30?

Question: Level 30 is the max level for a Summoner, but how much XP does it take to get there? About how many 5v5 matches does it take to get that much (assuming 50% win/loss ratio)?
Answer: According to the wiki, it takes 40083xp.
Also from the wiki:

Assuming an average XP gain to be about 110 XP per game, one can reach summoner level 30 within 365 normal games.
Comment: with a game averaging at 30 minutes, 365 games is A LOT.
Comment: Please note these are averages as best as they could be given. There are the first win of the day bonuses, each one varries but a bit for quick win, long defense, etc. They run promotions all the time.
Answer: Adding to the previous response, you can purchase XP boosts from the store to help you gain more points per win if you are really interested to get to level 30 faster.  Please understand the competition for the most part have won about 150 games to level 30 so the faster you progress the less time you have to develop the necessary skills to play at the higher level.