Book recommendation about mathematics

Question: I'm looking for a book about mathematics, but not about calculus, algebra or any field of math. I want to read a book about the use of mathematics in the world, for example, Why is math so useful. Or maybe something about the point of view of a mathematician in the world or even a biographyy of someone math related.
 Any book related to math (but not with the theorems/definitions/integrals/etc) I will take in consideration. Thanks
Comment: What Is Mathematics? An Elementary Approach to Ideas and Methods 2nd Edition by Richard Courant (Author), Herbert Robbins (Author), Ian Stewart (Editor)
Comment: I think it would be helpful to pin down a bit more regarding th criteria, otherwise the question strikes me as too broad, perhaps it can be a big list, or community wiki?  A two sentence answer half of which is the citation of a book (no different than a link only answer) should be open for deletion, @Warlock.
Comment: No book recommendation, but a hint: Mathematics is the science of structure. And since there is structure everywhere you look, mathematics is everywhere and thus very useful.
Comment: While not a book recommendation, I'd like to suggest watching all of George Paul Csicsery's films at [zalafilms.com](http://www.zalafilms.com). [Hard Problems](https://www.youtube.com/watch?v=m8KCx1DFnQI) is a good place to start.
Comment: Why is this question already closed for answers? The existing answers do not even give a close approximation to the choice of books which are available.
Comment: @MartinPeters note that the question was put on hold as "too broad." That is, 'the existing answers do not even give a close approximation to the choice of books which are available,' is in not in contradiction with the rationale for putting the question on hold but instead supports it.
Comment: @quid Well, but one could still give some reasonable reply with useful information to MathScientist.
Comment: @MartinPeters there are already any number of not all that clearly defined list of books floating around. I for one fail to see the point of creating yet another one. As for OP, they accepted an answer. Maybe once they looked at some of the recommendations they can ask a more focused follow up question.
Answer: "A Mathematician's Apology" by G.H. Hardy  can be a good starting point. It is a classic from the '40, also written by an incredible Mathematician.
Disclaimer
This as to be intended as an answer to the questions " book about the use of mathematics in the world", "something about the point of view of a mathematician" and "biography". It certainly addresses also the topic of the usefulness of Mathematics to the human society but, the author instead of providing arguments to prove that Mathematics is "so useful" will try to show that the true and beautiful Mathematics is useless to the society. This has to be intended in a good way since Hardy, who was a pacifist, wanted to take distances from the possible (negative) applications of Mathematics to war.
Comment: To recomment Hardy "about the use of mathematics in the world" is rather ironic (not sure GHH himself would have agreed to see his name mentioned here).
Comment: Well, for sure he speaks about the usefulness, applications and beauty of the mathematics, and that's the point. The particular position he had on this topic is not relevant.
Comment: If the particular position in question is that the essence of mathematics is to have no use in the world, then, sorry but this seems quite relevant.
Comment: The answer still fits almost all the requisites of the question: "book about the use of mathematics in the world", "Or maybe something about the point of view of a mathematician in the world" or  "even a biography of someone math related". The only thing **partially** not addressed is "why is math so useful".
Answer: A good idea-since you are after all a Maths student-would be "Mathematics Made Difficult" by Carl E. Linderholm.
Comment: Lol, I like the title!
Answer: Then what about start and reading about the historical development of math ?
For instance I found very interesting A History of Mathematics-Carl B. Boyer.
Answer: Currently I am reading How Not To Be Wrong: The Power of Mathematical Thinking (Amazon Link). That sounds like what you are looking for, and so far I'm quite enjoying it.
Answer: One of my favorites is Beyond Numeracy bu John Allen Paulos (1991).  It's written "magazine style," with about 60 short essays describing various mathematical subjects and why they are important. Some of the essays are of an theoretical nature, but many do describe examples or real world use and why math is so useful.  From the book flap:

"...presents in engrossing fashion a broad range of mathematical
  concepts, from the basic to the advanced, that have transformed our
  civilization."

I read it my very first semester in college.  I didn't understand everything in it. But it is very accessible.
Answer: "What is mathematics, really?", by Reuben Hersh. From the blurb:

In what sense do mathematical objects exist? How can we have knowledge of them? Why do mathematicians think mathematical entities exist for ever, independent of human knowledge?
Answer: On "Why is math so useful?", this is a question that's been discussed in recent years by philosophers of science and philosophers of math.  Mark Colyvan's An Introduction to the Philosophy of Mathematics includes a bit of dicussion of this subject, and should have pointers to others' work on the topic.  Mathematically, the book seems quite accessible to someone who's already quite comfortable with math.  It is definitely introductory with respect to philosophy (of math), but philosophical thinking about something like math can seem foreign at first to some people.
To give you some context to how I'm interpreting your question, in a very informal way:  Sometimes mathematical entities--numbers, sets, structures, etc.--seem to live in a realm of their own.  Some mathematicians and philosophers think about math this way.  Yet math seems to be essential to the ways that science learns about physical world.  These two perspectives seem to conflict, so some adjustment to thinking about math and science seems necessary. There are different ways to do this.

Book recommendation about mathematics


Can't get second level routes working in express

Question: I'm sorry I'm reasonably new to node. I've been stuck on this for a couple hours.
server.js
app.use(express.static(__dirname + "/public"));

app.get('/', function(req, res){
  res.sendFile(path.resolve(templatesPath + 'index.html'));
});

app.get('*', function(req, res){
  res.sendFile(path.resolve(templatesPath + 'index.html'));
});

index.html is an Angular application. I have the first level of routes working fine using Angular's HTML5 routes eg. "http://lh:3000/staff" or "http://lh:3000"
but if I add another level or route parameters, e.g. "http://lh:3000/staff/" or "http://lh:3000/staff/test" Express seems to ignore express.static and instead uses the get wildcard to turn all my files into index.html so my page breaks.
Thanks for your help answerers
In secondary routes, it was loading assets referenced in index.html, relative to the secondary route. My temp solution is to add:
app.use('/files/',express.static(path.join(__dirname + "/public")));
but I realise now it is better to change my solution.
Answer: are staff/test, static assets sitting inside your assets folder?
If they are static assets, there must be a file in the path staff/test inside your assets folder.
if they are not static assets and they are dynamic content, consider using express.router,make a router for staff and add it as,
var staff = express.Router();
staff.use('/staff', staff)

//this is route handler for /staff/test
staff.post('/test', function(req, res, next){
  res.json(some-json-content)
})

Comment: Thanks, I was not aware of Routers. I need to sleep now but I'll look into it tomorrow and post my answer when I come up with it
Answer: try this:
app.get('*/*', function(req, res){
  res.sendFile(path.resolve(templatesPath + 'index.html'));
});


How to enter Erlang Mode in Emacs?

Question: How do I enter erlang mode in emacs to get syntax highlighting? Whenever I open an erlang file nothing special happens. Do I need to change something in my .emacs file, or do I need to add a module to emacs, or something else?
Answer: Emacs doesn't come with an Erlang mode, so you need to add one. Erlang itself appears to ship with an Emacs mode that you can use; there are instructions on installing it and using it on their website, but it comes down to just adding their folders to your load path and exec path, setting a variable, and requiring the module:
(setq load-path (cons  "/usr/local/otp/lib/tools-<ToolsVer>/emacs" load-path))
(setq erlang-root-dir "/usr/local/otp")
(setq exec-path (cons "/usr/local/otp/bin" exec-path))
(require 'erlang-start)

The paths might be different depending on where you installed Erlang
Comment: thanks. how do i find where otp is installed? is there an erl command for it?
Answer: As of 22 March 2013, the Erlang mode is installable through the MELPA package archive.  If you haven't done so already, activate MELPA by putting the following in your .emacs:
(add-to-list 'package-archives
  '("melpa" . "http://melpa.milkbox.net/packages/") t)

Then hit M-x list-packages and install the erlang package.

How to enter Erlang Mode in Emacs?


Catboost overfits training data but test performance increases

Question: I'm training catboost on a dataset made of 41k observations and ~60 features. The dataset is a longitudinal series (9 years) that is spatially distributed. At the moment I'm just using random resampling of data, ignoring spatial and temporal dependencies. The model selection is performed using a 5 folds CV and some data are used as external test/held out set.
Best result I get with catboost is with following hps:
mtry=37, min_n = 458, tree_depth = 10, learn rate = 0.05
training AUC = .962
internal validation AUC = .867
external test AUC = .870
The difference between the training and test AUC is quite big and this suggests overfitting.
A second hp configuration, instead, reduces the difference between the training and test set but the test performance decreases as well.
mtry=19, min_n = 976, tree_depth = 8, learn rate = 0.0003
training AUC = .846
internal validation AUC = .841
external test AUC = .836
I'd be tempted to go with the first hps configuration since it gives me the best result on the test set. On the other hand the second result seems more robust to me, since training and test performance are quite similar. In addition the second result might be closer to the "true" performance I can get using spatial or temporal blocked resampling strategy.
Then my question is should I be concerned about differences between training and test set or as long as the test performance doesn't decrease (overfitting consequence) I shouldn't care about it and pick the first hps configuration?
Answer: Your intuition that "the second result might be closer to the 'true' result" is good. In a scenario where a model is overfitting, take even the performance on a validation and test set with a grain of salt. It could be that the pattern the model memorized for training still performs well on validation and test for now, but is a strong signal that the model is inflexible to variance, which in most cases is likely to occur with time.
Therefore, yes, you should be concerned about differences between training and test, and not simply select the model which has the best test performance. The difference in test performance between these two models is relatively small. Based on the little I know of what you have tried, I'd suggest iterating more to see if you can recapture a few points of accuracy while still eliminating the overfitting.


What's the difference between $|x_1+x_2\rangle$ and $|x_1\rangle+|x_2\rangle$?

Question: In quantum mechanics, we very often deal with ket vectors. Usually if two vectors belong to the same vector space, we can add them component wise. But my question is that is it permissible for ket vector? Like can I add $|x_1\rangle + |x_2\rangle$ to get $|x_1+x_2\rangle$? Cause I don't think both correspond to the same physical thing. Please enlighten me.
Comment: [Related](https://physics.stackexchange.com/q/728173/).
Comment: Is there any reason you did not accept an answer yet?
Answer: You can certainly add any two kets together. However, assuming that you're referring to (generalized) position eigenvectors, the result is not $|x_1+x_2\rangle$.

Imagine that the Hilbert space is given by $\mathbb C^2$, the ordered pairs of complex numbers.  Given the operator
$$A := \pmatrix{1&0\\0&2}$$
I can define the states
$$|1\rangle \equiv \pmatrix{1\\0} \qquad |2\rangle \equiv \pmatrix{0\\1}$$
where we have that $A|1\rangle = 1 |1\rangle$ and $A|2\rangle = 2|2\rangle$.  I can certainly add $|1\rangle+|2\rangle$ if I wish; the resulting element of $\mathbb C^2$ would be $\pmatrix{1\\1}$.  However, I can't say $|1\rangle+|2\rangle = |3\rangle$ (not least because the right-hand side has not even been defined).
In terms of (generalized) position eigenvectors with the Hilbert space $L^2(\mathbb R)$, $|x\rangle$ and $|y\rangle$ are eigenvectors of the position operator with eigenvalues $x$ and $y$, respectively. Crucially, note that $x$ and $y$ are labels for our vectors. While there is a state whose label is $x+y$, it is not given by $|x\rangle + |y\rangle$ for the same reason that $|1\rangle+|2\rangle \neq |3\rangle$ above.
Answer: No, those are different vectors. The Hilbert space used here is a free vector space (See here) equipped with a canonical scalar product. (In general, there is a construction called free object (See here) in category theory, which is basically a mathematical structure like a group generated by a set.)
In the case of a free vector space, you take a field $\mathbb{K}$ and a set $X$ and then make the latter the basis of your vector space. That means the elements of this vector space are formal sums of the form:
$$\sum_{x\in X}\lambda_xx$$
with $\forall x\in X\colon\lambda_x\in\mathbb{K}$. The free vector space itself is also often written $\mathbb{K}\otimes X$ for this reason. Of course, its dimension (the cardinality of a basis) is the cardinality of the set.
In quantum mechanics, you consider the free vector space generated by the underlying set of the vector space $\mathbb{R}^n$ (Note, that the new free vector space is not $\mathbb{R}^n$ again for it has infinite dimension while $\mathbb{R}^n$ has finite dimension) and consider all the basis vectors generating the free vector space to be orthogonal:
$$\langle x|y\rangle=\delta(x-y).$$
$|x_1\rangle$, $|x_2\rangle$ and $|x_1+x_2\rangle$ are therefore three different and distinct basis vectors, that are pairwise orthogonal to each other and $|x_1\rangle+|x_2\rangle$ is a formal sum like in the equation above. Basically, since infinite dimensional spaces are hard to imagine, take $\mathbb{R}^3$ with the three basis vectors $e_1$, $e_2$ and $e_3=e_{1+2}$. I used $1+2=3$ here to highlight, it's really just about the name of the vector. We have:
$$e_1+e_2
=\begin{pmatrix}
1 \\ 1 \\ 0
\end{pmatrix}
\neq\begin{pmatrix}
0 \\ 0 \\ 1
\end{pmatrix}
=e_3=e_{1+2}.$$
Now fill this example up with infinitly many zeros and you have the same in a free vector space.
Answer: To add to the other answer, some books define $|aA+bB\rangle$ as equal to $a|A\rangle+b|B\rangle$.The former is just a shorthand notation for the latter. In that notation, the $aA+bB$ written inside the ket is only a name for the ket.
But this notation can get confusing with position kets, like the other answer showed. $|x_1+x_2\rangle$ can either mean $|x_1\rangle+|x_2\rangle$ (if we're using the notation), or it can mean a position ket with eigenvalue $x_1+x_2$. I think the latter interpretation would be standard.
Comment: Can you include examples of books using this horrible inconsistent notation?
Answer: I actually don't understand why do you think that $|x\rangle+|y\rangle=|x+y\rangle$. Yes, we can sum vectors in a vector space, in particular we can sum $|x\rangle+|y\rangle$ but there is absolutely nothing suggesting it should be $|x+y\rangle$. In fact, maybe one example clears this. Let me define a function depending on a parameter $x\in \mathbb{R}$: $$f_x(x')=\sin(x-x').$$
Now, we may obviously sum functions, so we may consider $f_x+f_y$. Is it the case that just because we can sum functions we have $f_{x+y}=f_{x}+f_y$? In this case this is obviously not true, as is the case for the position eigenstates.
On the other hand, perhaps the way to convince you that $|x+y\rangle$ and $|x\rangle+|y\rangle$ are different is to understand how they are used and to give an explicit counterexample. The position basis $|x\rangle$ is used to project states $|\psi\rangle$ to get the associated wavefunctions $\psi(x)=\langle x|\psi\rangle$ so that we may expand the state $$|\psi\rangle=\int dx \psi(x) |x\rangle\tag{1}.$$
In particular, the possible $\psi(x)$ in (1) are elements of $L^2(\mathbb{R})$, the space of square integrable functions on the real line.
Now, let $|\psi\rangle$ be an arbitrary state. Equality between $|x+y\rangle$ and $|x\rangle+|y\rangle$ would mean $$\psi(x+y)=\langle x+y|\psi\rangle=\langle x|\psi\rangle+\langle y|\psi\rangle=\psi(x)+\psi(y)\tag{2}.$$
In other words, a generic $\psi(x)$ would have to be linear and this is certainly not true. In fact, we may consider gaussian states by picking $\psi(x) = e^{-\alpha x^2}$. This is an element of $L^2(\mathbb{R})$, we have the associated $|\psi\rangle$ as given in (1) and (2) is simply not true for it.


the difference between taunt and ridicule

Question: which one of these words is used as everyday English as well as means to despise someone and make fun of him for example because of his shape or Social status and so on
Comment: I think of taunting (but not ridiculing) as soliciting a reaction - like provoking, but I don't see that connotation mentioned in definitions.
Comment: They both are reasonably common (although the most "everyday" expression for me would be "make fun of"), and both could be used in that situation.
Answer: Ridicule and Taunt are very similar in meaning, but taunt has the additional meaning of inciting the person who is being taunted to a response.

Adolph, enraged at this taunt, flew furiously at his adversary,
  swearing and striking on every side of him  (Harriet Beecher Stowe, Uncle Tom's Cabin), quoted in The Free Dictionary

ridicule, The Free Dictionary

The act of using words, gestures, images, or other products of expression to evoke laughter or contemptuous feelings regarding a
  person or thing: a remark that invited the ridicule of his classmates.

taunt, The Free Dictionary

To reproach in a mocking, insulting, or contemptuous manner: taunted her for wearing hand-me-down clothes. See Synonyms at
  ridicule.

2a  To drive or incite (a person) by taunting: His friends taunted him into asking for a raise.
2b  To tease and excite sexually: taunted him with glimpses of skin
(emphasis added)
Comment: Please note this refers to someone called Adolph, not [Adolf](https://en.m.wikipedia.org/wiki/Downfall_(2004_film))
Comment: It was meant as a joke.
Comment: I agree with this difference (said so in a comment), but I did not see this connotation in a quick google of definitions. For me, it typically has this connotation of provoking or inciting a response.
Answer: Where I do agree on the answers given by the others, I wanted to add this:
When taunting the intended receiver of your message is the person you are taunting. The purpose of the taunt is to get a reaction from that person (or animal).
When ridiculing the intended receiver of your message is whomever is your audience at the moment, and it doesn't need to include the person (or animal or thing) being ridiculed. The purpose of ridicule is to lower other peoples opinion on whomever or whatever you are ridiculing.
Both taunting and ridiculing doesn't require words to be effective. To ridicule someone (especially in front of someone they admire) is often a very effective taunt and getting an explosive reaction from a taunt in front of others is often effective ridicule. I would wager that is the most common use of taunting in our modern society. Taunting was used a lot in battle (and still is) to make the opponent make a unfavourable move out of anger.
In pen and paper role playing games and video games there will often be a skill or action called taunt that can be used by the tank (the one who is tough and is meant to take most of the hits) to attract the attention of the foes so they will favour him/her over other targets even though hitting them would be strategically more favourable.
Answer: Merriam-Webster's Eleventh Collegiate Dictionary treats ridicule and taunt as fairly close synonyms, in a cluster that also contains deride and mock. A Google Ngram chart of the four expressions over the period 1900–2005 shows that ridicule (blue line) and mock (green line) are considerably more common in published texts than taunt (red line) and deride (yellow line):

The most striking thing about the chart is how stable the frequency of usage has been for three of the four words (all except ridicule) over the charted period.
In any event, here is the Eleventh Collegiate's note on how the meanings of the four words differ:

RIDICULE, DERIDE, MOCK, TAUNT mean to make an object of laughter of. RIDICULE implies a deliberate often malicious belittling {consistently ridiculed everything she said}. DERIDE suggests contemptuous and often bitter ridicule {derided their efforts to start their own business}. MOCK implies scorn often ironically expressed as by mimicry or sham deference {youngsters began to mock the helpless wino}. TAUNT suggests jeeringly provoking insult or challenge {hometown fans taunted the visiting team}.

So you have two considerations to bear in mind: the commonness of the term, and the particular connotations of the term. Both ridicule and taunt are widely used and understood words, although ridicule appears to be more common; but the implications of the two words (if we are to believe Merriam-Webster) are somewhat different.
(As a final note, I should point out that ridicule and taunt can be either nouns or verbs, whereas mock can be either a verb or an adjective, and deride is strictly a verb. So the advantage in frequency that mock has had over ridicule since the 1970s, according to the Ngram chart above, may actually understate the advantage that the verb mock has over the verb ridicule, or it may reflect, in part, the popularity of mock as an adjective.)
Comment: +1 for mentioning the noun forms. You can have "a taunt", but you can't have "a ridicule".
Answer: Taunt is personal:

to say insulting things to (someone) in order to make that person angry.

A taunt can consist of ridicule ("Your mama wears army boots"), but doesn't have to be about anything or even derogatory; a simple "Nyahh, nyahh, nyahh" is a nonspecific (childish) taunt. In order to be a taunt, the taunter expects the person being taunted  to be paying attention.
Ridicule is not personal:

making fun of a person or thing, usually based on a specific characteristic, deserved or not.

But ridicule doesn't have to be directed at a person. One might ridicule a political opponent's opinion to people who agree with you ("preaching to the choir"). Or you can ridicule something or someone when you are all by yourself.


Is there a way to get Terminal on Lion to start up cleanly (without the buffered history)?

Question: How can I prevent Terminal from showing me my old output when it starts?
I would like it to always start with a clean window.
Answer: You can change terminal only with this one command to write a new preference for that specific app.
defaults write com.apple.terminal NSQuitAlwaysKeepsWindows -bool false

This is general, so of course, substitute safari or quicktimeplayerX or whatever in the com.apple.terminal portion of the command as needed. This setting switches the default save behavior upon quitting that one app. You'll find many of the other apps that work well with this setting by searching on NSQuitAlwaysKeepsWindows.
Of course, you should issue this defaults command after closing all windows and then quitting the application to ensure the settings are read the next time Terminal starts.
Comment: You can also close all the windows when quitting. Sometimes I like it to be clean. Sometimes I like retaining the old output.
Answer: Besides setting the preference to always suppress Resume, you can also control this when quitting by pressing the Option modifier key, so that "Quit …" becomes "Quit and Discard Windows". e.g., you can type Option-Command-Q to quit without saving state. You can also press the Shift modifier when an application is opening to prevent it from restoring state for Resume.
There is also a Terminal preference (without UI) for controlling how many lines of the scroll-back to restore, which you can set to zero, although it still restores the display contents:
defaults write com.apple.Terminal RestoreScrollbackLines 0

Answer: There seems to be one case where disabling NSQuitAlwaysKeepsWindows does not work: When the Terminal is killed by killall Terminal, and probably also when it crashes or when it is forced quit.
I use killall Terminal regularly, but when the resume kicks in, it messes up my bash history. Basically, commands from the session after the resume will not be saved. Normal saving behaviour is only restored after I quit and reopen Terminal.app. It appears, though, that completely disabling any resume features fixes bash history:
chmod a-rwx ~/Library/Saved\ Application\ State/com.apple.Terminal.savedState

Thanks to willWorkForCookies's answer to How to prevent one app from saving/restoring any Saved State.
Answer: You can actually deactivate "save state" on per-app basis, have a look at https://faqintosh.com/risorse/en/sys/swapsaveability/
HTH
Comment: Welcome to Apple! Whilst this may theoretically answer the question, [it would be preferable](http://meta.stackexchange.com/q/8259) to include the essential parts of the answer here, and provide the link for reference.
Answer: The only way to do this is to completely disable the resume feature in Lion
http://www.macrumors.com/2011/07/20/how-to-disable-lions-resume-feature/
Comment: This does work, but it's overkill since `defaults write com.apple.terminal NSQuitAlwaysKeepsWindows -bool false` will quash this behavior on terminal only.


Can I reflash stock with kies

Question: I'm on a Samsung Galaxy s4 sgh-i337 from att and I messed up my system a little bit I want to reflash and restore stock firmware with kies. Will that work?  Also, I am rooted will kies work with me?
Answer: It should, but if it doesn't, it won't hurt to manually flash your stock firmware with Odin.
It's also worth noting that Kies sometimes has trouble recognizing devices which no longer boot up normally (speaking from experience); in which case you would be better off using Odin or Heimdall.
Comment: Kies just ended up messing up my phone and so I used Odin to flash stock firmware. Using Odin was a lot easier than I thought

Can I reflash stock with kies


'Helping' as a noun/gerund/ present participle?

Question: "Thanks for your advice - I found it very helping."
Is this use of 'helping' correct in the above sentence? Thanks a lot.
Comment: It should be an adjective because it's modified by 'very', which does not verbs (cf. the unacceptable *she is very walking). But your sentence doesn't sound idiomatic (and is potentially ungrammatical) to me; 'helpful' is a more common adjective.
Answer: While technically this is possible- the gerund form does exist, I believe it would be better expressed with helpful.
Answer: There is a fixed phrase:

She lent him a helping hand.

That is, she helped him.
And the -ing form often appears to be adjectival, expressing the kind of something:

He bought a new pair of running shoes.
Gutenberg is credited with the invention of the printing press.

But we don't normally use helping as a predicate adjective / subject complement:

Your advice was very helping ungrammatical.

Yet with some other -ing forms we would have no problem using them in that manner:

Most men found Morgan beguiling.
The question is intriguing.
The experience was enriching.
A mother's voice is often soothing.
The algorithm was self-adjusting.
She's too judging, always finding fault.
The story was very amusing.
Why are you always so accusing?
The thought of sailing to Tahiti was most alluring.
The amount of lead in the drinking water was quite appalling.
The chocolate cake looked very appealing.
The nod was approving.
The jacket felt too constraining.


Studying QGIS generated TIFF images for water flow/resources

Question: I am new to QGIS. I have created tiff images from MODIS data using QGIS. I want to study the water flow/resources from those images. As I am new to this field I don't understand how to study those images. Please help me in this regard. Please provide me any suggestion, link or tutorial from where I can understand how to study those images for water flow or resources.
Answer: i think you should check out grass plugin for your study. it has lots of raster analysis as Hydrologic modeling toolbox. you can check out GRASS GIS 6.4.3svn Reference Manual here

Watershed modeling related modules are r.basins.fill, r.water.outlet,
r.watershed, and r.terraflow. Water flow related modules are r.carve,
r.drain, r.fill.dir, r.fillnulls, r.flow, and r.topidx. Flooding can
be simulated with r.lake. Hydrologic simulation model are available as
r.sim.sediment, r.sim.water, and r.topmodel.

r.flow - Construction of slope curves (flowlines), flowpath lengths, and flowline densities (upslope areas) from a raster digital elevation model (DEM).

r.watershed - Watershed basin analysis program.

r.water.outlet - Watershed basin creation program.

r.drain - Traces a flow through an elevation model on a raster map.

and getting some fundamental information you can glance at The GRASS GIS software (with QGIS) - GIS Seminar, here
i hope it  helps you...
Answer: Also, an image is an optical view.  If you are looking at doing watershed modeling, which it seems you are, then you will want to have elevation data (DEM) and an idea of where water sources are.  Depending on where in the world you are looking to study, there are a number of DEM data sources available, at ranging resolutions, for free.


Scaling Mat elements to [0..255] range with OpenCV on Android

Question: I am trying to convert some OpenCV python code to Java and I ran into a problem of finding the correct functions in Java wrapper. The python code in question is calculating the Scharr gradient along the x-axis as:
# compute the Scharr gradient of the blackhat image and scale the
# result into the range [0, 255]
gradX = cv2.Sobel(blackhat, ddepth=cv2.CV_32F, dx=1, dy=0, ksize=-1)
gradX = np.absolute(gradX)
(minVal, maxVal) = (np.min(gradX), np.max(gradX))
gradX = (255 * ((gradX - minVal) / (maxVal - minVal))).astype("uint8")

[Code is from pyimagesearch website - Detecting machine-readable zones in passport images - blog post]
What I have in Java is:
Imgproc.Sobel(blackhat, gradX, CvType.CV_32F, 1, 0, -1, 1.0, 0, Core.BORDER_DEFAULT);
Core.convertScaleAbs(gradX, gradX);
Core.MinMaxLocResult minmax = Core.minMaxLoc(gradX);

This should output the same result as the first three lines of the python code. But I got stuck on the last one. How does one perform the scaling of the gradX back into the [0..255] range with Java API?
Also does the convertScaleAbs function perform the same action as NumPys absolute?
Comment: any luck?? I am stuck at the same location.
Comment: Nope! Sorry....
Answer: Use normalize with normType=NORM_MINMAX.


How to make applescript type items into url bar

Question: How do i make applescript type certain things such as urls into the url bar?
I've been trying to set up my computers so I don't take 9 years to set everything up when I need to work.
I have most of it ready but I can't figure this part out...
Can someone help me?
Comment: What Browser are you using?
Comment: Does it have to be AppleScript? You can use `open https://google.com` from command line directly
Comment: I use Google Chrome.
Answer: This works with following AppleScript lines:
tell application "Safari"
open location "https://google.ch"
activate
end tell

Answer: In my case browser, Safari, I do the following:
1. Set Safari to open new windows with favorite
Now when you launched Safari or when you write an AppleScript to activate Safari.app, Safari opens with URL box ready. From then you can just type in your desired URL.
My example script below will open a new tab by pressing Command+T (key code 17), then started typing in "google.com"
tell application "Safari" to activate
tell application "System Events"
    key code 17 using command down
    keystroke "google.com

If your computer is slower, you may find adding delays (denoted in seconds) between command lines helpful:
tell application "Safari" to activate
tell application "System Events"
    delay 0.5
    key code 17 using command down
    delay 0.1
    keystroke "google.com

Comment: Probably the worst possible way to achieve the end goal that one could ever imagine.  But I do like how nicely formatted your answer is.  It's very clear and easy to read.
Comment: Oh thank you for your comment. I'm pretty noob and so I just spontaneously answered this thread without revising or researching based on how I "naturally" achieve this ie by openning new tab with keyboard shortcut and typing in the URL. I even forgot to end tell and whatsoever lol. This has cheered me up.


Activate/Deactivate action on Product list

Question: In the Product list table you have an Activate/Deactivate action links (the left column).
When I click these the action does not fire the On Update trigger I have.
If I implement a custom button to change the Active field the trigger is fired.
This is my trigger definition:
<code>trigger ProductTriggers on Product2 (before insert, before update, after insert, after update, after delete) {

}
</code>
Has anyone ran into the same problem?
Is it a bug?
Answer: I just confirmed this is happening in my dev org as well. It also looks like others are running into this issue as well. Stolen from a link on the Developer Boards by sfdcfox,

I've confirmed this behavior. It's calling the standard edit
  controller ( /{!Product2.Id}/e?act=0&retURL... ) that does not have
  the usual save=x parameter (where x is any value, but usually the word
  Save). It seems to bypass all validation, workflow, and trigger logic.
  Nothing shows up in the debug logs at all. I suspect that this is a
  bug, and you should report it to Technical Support.

sfdcfox also posts a workaround to solve this:

...if you
  override the product2.edit action with a Visualforce component, you
  can perform the update in your custom code, which fires your trigger
  correctly. This is only a shortterm solution, as it introduces a CSRF
  attack, but is no worse than the original problem, which is also CSRF
  vulernerable. Alternatively, have the edit page offer them a chance to
  cancel or confirm the action so you yourself prevent the CSRF attack.


Should chemistry students worry about quarks and such?

Question: Even chemistry textbooks less than five years old start by describing atomic structure based only on protons, neutrons and electrons. Is an understanding of chemistry fundamentals likely to become out of date when the textbooks start to include quarks, leptons and the dozens of other sub-atomic particles?
Comment: There are only two types of fundamental particles in chemistry: electrons and nuclei.
Comment: Why would they start to do it?
Comment: There actually have been studies of [chemistry based on particles other than electrons, protons and neutrons](http://en.wikipedia.org/wiki/Exotic_atom), especially [using muons](http://en.wikipedia.org/wiki/Muonium) (which are leptons, not quarks). However, as the name "exotic atom" evokes, it's some very particular stuff.
Comment: Well in my humble opinion a true scientist always pursues to expand their knowledge about the inner workings of nature. Therefore, if you like science you should attempt to at least understand something of everything.
Comment: Muons are pretty important in solid state chemistry; look up spin polarized muon spectroscopy...
Answer:
Is an understanding of chemistry fundamentals likely to become out of date when the textbooks start to include quarks, leptons and the dozens of other sub-atomic particles?

Well, the general chemisty books do already include leptons, at least electrons and usually positrons.
Other than protons, neutrons, electrons and positrons (and photons), I think that when discussing beta decay and electron capture, neutrinos and antineutrinos should be included, otherwise the nuclear reactions aren't really balanced (lepton number must be conserved).  Alternatively, the general chemistry books could omit all discussion of nuclear reactions, as being physics.
Other than that, I think the rest of the particles can wait for physics class, rather than general chemistry class.
Beyond general chemistry, other particles are sometimes discussed in more advanced chemistry books, such as quantum chemistry texts, where examples involving muons are common.
For some chemistry topics, such as isotope differences in rotational-vibrational spectra of small molecules distinction between fermions and bosons is critical.  Trying to explain the difference between fermions and bosons (and Fermi-Dirac statisitics vs Bose-Einstein statistics vs Boltzmann statistics) naturally leads to discussion of the standard model and the particles in the standard model.  So by the time a student gets to physical chemistry, around the third year of college, they should have some understanding of the standard model.
Answer: Chemistry is governed by what electrons do, and generally... what valence electrons do.  There really is no need to dive into subatomic particles.  It may help explain what keeps a nucleus held together but we generally gloss over that aspect and simply have students accept this as a fact.  Subatomic particles, of which there are many, are generally covered in physics.  We usually touch upon them in nuclear chemistry when decay processes are introduced.
The main point here is that Chemistry is essentially all about what the electrons are doing.
Answer: I mean to be honest with you, when I was in Chem 1, we never went into the details of quarks and other sub-atomic particles except once; in nuclear chemistry. Even then, you didn't have to have an idea of these subatomic particles to understand what was going on.
So, if you think about it, wouldn't they (teachers) have changed the curriculum to include, other, dozens of subatomic particles if it was needed?
Although, you still have a good point. But, overall, from my definition of a chemistry student, I wouldn't think that worrying about quarks and other subatomic particles.
Answer: The real question is not 'Why don't books include X?', but 'What would change if books included X?'.
To the best of my knowledge and understanding, what protons, electrons and neutrons are is fundamental to understanding a wide range of stuff that happens in chemistry. (Yes, neutrons play a role for deuterium exchange effects etc.)
However, there is hardly anything that would change if descriptions included lower-level particles like quarks. I can't think of any chemical reaction or other chemical process that cannot be sufficiently explained only going back to protons, neutrons and electrons — usually, even neutrons are irrelevant. So basically, you're suggesting increasing complexity with no added benefit to the learner. Why would one do that? Just for the sake of correctness? If anything, a note that protons and neutrons are made up of smaller particles suffices for any beginner's level textbook.
In fact, there is quite a lot of chemistry that can be just explained with the concepts of atoms and bonds. The only reason why the sub-atomic particles are included in the first place, is because salts are introduced early and can be explained a lot better, if electrons and nuclei are known. (And it eases the explanation of 'what exactly is a bond?')
Answer: I'm going to take a shot at this question from a different angle, aiming for a more objective analysis. For that, I wish to bring up several concepts. Bear with me!
First of all, what do we mean when asking if something is relevant or not to Chemistry? A precise and exact definition is not trivial, but let us consider a simple argument: chemical reactions are pretty important in Chemistry! In other words, we like to see atoms swapping around positions. It turns out that we have a fair idea of how quickly these events happen. We know that bonds in molecules vibrate at certain frequencies, which is how infrared spectroscopy works. The quickest bonds to vibrate do so at around $\rm{3500\ cm^{-1}}$, which implies a frequency of about $\rm{10^{14}\ Hz}$. This establishes a useful timescale - the fastest atomic displacements relevant to bonding in a molecule happen on the order of $\rm{10^{-14}\ s = 10\ fs}$. This means even the fastest chemical reactions need at least about this much of time to happen. Any event which begins and ceases within a timescale much shorter than $\rm{1\ fs}$ means that molecules don't even have time to react to the event. Even a molecule in a reaction transition state, as short-lived as it is, would be essentially frozen during time intervals much smaller than this. There are important processes which happen faster than $\rm{1\ fs}$, such as electronic transitions and nuclear decay, but they are important in Chemistry because what matters here is not how long the transition takes, but that the resulting state is sustained for around $\rm{1\ fs}$ or more before it decays. As an interesting aside, virtual electronic states used in Raman spectroscopy exist for times as long as $\rm{0.1\ fs}$, which further shows how this scale is too quick for molecules to respond.
Now for subatomic particles. Not counting antiparticles, there are at least 17 types of fundamental particles (though 4 of those are force carriers, and the Higgs boson is something else entirely, so we'll put those aside), and over a hundred composite subatomic particles. Yet, for some reason, almost all of Chemistry only deals with three fundamental matter particles (the electron, up quark and down quark), and two composite particles (protons and neutrons, i.e. the up-up-down and up-down-down triquarks, respectively). Why is that so?
Without getting into the nitty-gritty details of particle physics, it turns out that particles tend to decay into their lightest possible relatives while obeying certain rules, such as charge conservation. Electrons are the lightest negatively-charged particle, so they are indefinitely stable (the same is true for positrons, the lightest positively-charged particle). Protons could conceivably decay into something lighter thanks to the positron, but in this case there is another type of conservation law which strongly forbids them to do so (baryon number conservation), so if they are not indefinitely stable, they are at least very long-lived ($\rm{10^{35}}$ $\rm{a}$ or more).
Neutrons are an interesting case. They're very slightly heavier than protons, by about 1%. This is enough to allow for decay, and indeed a free neutron has a mean lifetime of about $\rm{15\ min}$ before it suffers $\beta^-$ decay into a proton. If this happened to every neutron, the Universe would be filled solely with hydrogen, and life could not exist. Remarkably, the mass difference between protons and neutrons is small enough that it can be compensated by the stabilising nuclear forces inside the nucleus, and thus neutrons inside nuclei are stable with respect to decay for an amount of time comparable to the proton.
So up to now, we know that electrons, protons and neutrons are three examples of subatomic particles which are so long-lived that we can expect them to be relevant in chemical timescales. Are there any more? This is where things go awry. The next most stable subatomic particle other than the ones I just cited is the muon, a particle identical to the electron except for its larger mass, with a mean lifetime of just $\rm{2.2\ \mu s}$. This is still many of orders of magnitude more than the femtosecond benchmark established earlier, and in fact muons can display meaning chemistry, even taking part in reactions [1], [2]. However, you can imagine that processes involving muons are expected to be much, much rarer, and not have as much importance in chemistry. This is not to say that muons are irrelevant to Chemistry, just that they are of interest only in a much narrower range of circumstances relative to electrons, neutrons and protons. The problem is even worse for other subatomic particles, which often have much shorter lifetimes. Looking at some lists of particles, such as baryons, mesons and leptons, one sees just how short-lived they are; about half of them decay far quicker than $\rm{1\ fs}$ and could not even in principle partake in chemistry. There are still a couple dozen of particles which decay between $\rm{100\ ns}$ and $\rm{1\ fs}$, for which chemistry could exist at an even more limited scope, but again these are rarely relevant.
After all the information exposed above, should the average Chemistry student worry about these subatomic details? No, I don't think so. In fact if these issues were to be mentioned as more than a passing comment in when first teaching the structure of matter, I believe it would be counter-productive. That said, I do think it's a shame that an enormous majority of chemists never seem to peer a little deeper into the structure of matter, even years after graduating. It would be nice if at least knowledge of the fundamental particles were more disseminated. The Standard Model of particle physics is quite an amazing achievement, and there's more than enough beauty to appreciate even without breaking out the massive integrals!


When to use escape and escaped?

Question: A man trying to escape from deadly machine which is about to explode and at the same time victim saw that man is in dangerous situation but victim didn't see whether that man died or not after the machine exploded.
Thing is whether to use escape or escaped.
Comment: Additional context and examples wouold be helpful here.
Comment: Welcome to ELL.SE. Your question is rather unclear. *Escape* is a noun or a verb. *Escaped* is an adjective or the preterite of the verb. How you would use one or the other would depend on how you phrase the sentence.
Comment: Are you asking if you should use *a man trying to* ***escape*** or *a man trying to* ***escaped***? If not, you need to be be clearer about what you're asking.
Comment: Yes that's what I asked?
Answer: One could say or write

The man escaped.
The man was able to escape.
We don't know if the man escaped, because the witness could not see.
It isn't known if the man could escape or not.
The man failed to escape.
The man was unable to escape.
Had the man escaped, he would have been seen afterwards.

Many other variants using either "escape" or "escaped" are possible, depending on what meaning is intended, and whose point of view the sentence is beign written from.
Comment: No sir it was just an example and  created myself to clarify that word

When to use escape and escaped?


Is there a space between parenthesis at the end of a parenthetical remark?

Question: I wonder what to do about parentheses that follow each other, as in this phrase:
"(I have taken out my comments in the GoogleDoc (and corrected a couple of spelling errors thanks to Grammarly) )." I put a space between the last two parentheses, but don't know if that's proper or not.
Comment: Welcome to EL&U. Such matters are largely a question of style; adhere to the discipline of your editor, publication, or organization, or in the absence of a house style, adopt a [style manual](https://english.meta.stackexchange.com/a/2579) appropriate to your audience and tastes and be consistent in its application. See also *[Is there any rule for the placement of space after and before parenthesis?](https://english.stackexchange.com/questions/5987)*
Answer: Actually, you should not put parenthesis within parenthesis. It makes a mess of where the parenthetical statements begin and end. If you need to make a parenthetical statement within parenthesis, and commas do not suffice, you should use square brackets instead.
For reference, provision 162 of the Chicago Manual of Style (1st edition), which is found on page 58 of the book, states the folllowing:

Brackets are used to inclose an explanation or note, to indicate an interpolation in a quotation, to rectify a mistake, to supply an omission, and for a parenthesis within a parenthesis.

The last example the Chicago Manual of Style under this provision illustrates that there is no space between the closing bracket and the final parenthetical mark.

Grote, the great historian of Greece (see his History, I, 204 [second edition]),

It is more compact than including a space, while being less awkward and cumbersome than putting two closing parenthesis right next to each other.
Comment: The first edition of CMOS goes back to 1906, which seems long in the tooth for anything published today; I couldn't find an example of nested parentheticals in my 14th edition, which is not itself spry. (Not my downvote btw)


Can't get Netflix add-in for Windows 7 Media Center to appear

Question: Recently Netflix released their Windows 7 Media Center add-on to enable instant streaming. On one of my Windows 7 machines I triggered a manual download, and that installed the Netflix add-on just fine> However, on my other machine I can't get the add-in to appear. I've done a manual update multiple times, but it never shows up. Any idea on how I can get it to appear?
Answer: Here are the steps I used to fix the problem:

Open Control Panel/Programs and Features.
Click "Turn Windows features on or off" in the left pane.
Expand "Media Features", uncheck "Windows Media Center". Click "Yes" to continue, and click OK to quit. Then Restart.
Open "Turn Windows features on or off" again. Turn on the features "Windows Media Player" and "Windows Media Center". Restart.
Answer: I had the same problem, it turned out my Media Center wasn't configured for automatic updates. When I enabled it (go to Automatic Download options and click "Download now" as described here the updates were downloaded and the netflix menu has appeared.
Comment: Triggering the manual download has the same effect, but it didn't fix it in my case.


How to change the kernel on Kali Linux live usb persistence?

Question: I am using Kali Linux on a bootable USB with persistence. I have updated it using all the update/upgrade/dist-upgrade commands. When I tried to install VMware I noticed a problem with the kernel. It was still looking for the old version and therefore VMware will not open. By typing uname -r, I see that Linux is booting on 4.9.0-kali3-amd64 and not on 4.9.0-kali4-amd64 and when VMware runs it cannot find 4.9.0-kali3-amd64 as the update/upgrade downloaded the new kernel I guess. After I looked for solutions on the internet I found that because it is running on Live USB with persistence even after the update the kernel that Linux will boot on is the one from the downloaded ISO. But then I found this post: How to change the boot kernel of a usb live w/ persistent running Kali. This guy seems to have found a solution but I cannot really understands the steps he followed, more precisely I dont understand from where he moved initrd.img and vmlinuz to where. Can anyone elaborate?
Answer: I just followed his instructions and it does work with a few changes, below are the steps from the link you provided and my comments are in bulletpoints.

I first moved the initrd.img and vmlinuz from the /live folder on my usb to my desktop (for backup).

Make a backup of the files mentioned in ./lib/live/mount/persistence/sdxx/live.  Note sdxx may vary.

I then copied the initrd.img-4.9.0-kali4-amd64 and vmlinuz from my usb's persistence rw root folder to the /live folder.

copy files from ./boot/ to the location mentioned above.

I renamed these to initrd.img and vmlinuz and rebooted. Voilà

The rename task will vary depending on version I think, I did this using kali 2017.2 and found that the old kernel was booting using the full file name, initrd.img-4.12.0-kali1-amd64, not just initrd.img.

You maybe able to get away with renaming the new boot files to be exactly the same as the old ones. I didn't try this, instead I went to ./lib/live/mount/persistence/sdxx/boot/grub and created a new entry in grub.cfg to point to the updated initrd.img and vmlinuz files
Comment: Thank you @Camels for detailed explanation. How did you manage to copy files into ./lib/live/mount/persistence/sdxx/live folder in step 2? I tried that but it says that that folder is read-only.


Unable to add ICS Calendar Invites to iOS Calendar

Question: Problem
Calendar invites sent to my email (usually .ics attachments, as they originate from a customers' Exchange server) do not add and sync to my calendar. The UI to handle the calendar invite differs from my wife's phone (as evidenced in the screenshots below. Invites work as expected on her phone, but not on mine. This happens to be the case on all of my iOS devices (iPad, iPhone 11 Pro and iPhone 7).
My devices (all iOS 14.0.1)
iPad 6th Generation, iPhone 11 Pro, iPhone 7 (no SIM)
My wife's devices (iOS 14.0.1)
iPhone 11
Services (all inclusive and simplified, for troubleshooting)

iCloud Mail and Calendar DISABLED on both of our accounts
Google account connected, syncing Mail, Contacts and Calendars
Default Mail and Calendar on all accounts are not Gmail and Google Calendar

Detail (My devices)
When I receive a meeting invitation, there is an .ics attachment. When tapping on that attachment, I am presented with a card that has "Add to calendar" and "Delete Event" at the bottom.

My name appears in the invitee list with a gray "?"
Tapping on "Add to Calendar" brings up another card where I can choose the calendar to add the event to (in this case, I choose Personal Calendar, but it doesn't matter what calendar I choose, the results are the same).
I then tap "Done" in upper right corner
Card disappears
Event never shows up on calendar, and never syncs back to the cloud (Google, in this case, but could be iCloud, Outlook.com or Exchange)

Screenshot

Detail (Wife's device)
When she receives a meeting invitation (from same source), the same .ics attachment appears. When tapping on that attachment, she is presented with a card that has "Accept", "Maybe", and "Decline" at the bottom.

Her name appears in the invite list with a green "checkmark"
Tapping "Accept" immediately adds the event to her calendar (visible in iOS Calendar app as well as web version of Google Calendar

Screenshot

Troubleshooting

Performed a full factory reset and set up device AS NEW (not restored)
Deleted and re-added iOS Mail application
Installed Gmail application from App Store (to determine if that application provided different sync functionality to default iOS apps)
Installed Outlook app from App Store (Outlook RSVP also didn't work on any calendar)
INTERESTING NOTE: If Siri detects an event in the email message and I tap on the small bar at the top that says "Siri found 1 event", it WILL add to my calendar.

I am at a loss as to what could be different on my device or account that is preventing my Mail and Calendar from behaving as they should, and it is creating issue with meeting invites accepted while traveling. I have to actually accept on a laptop OR hope Siri finds an event and tap that to add it to the calendar.
Any help you all could provide would be appreciated!
Regards
Answer: On your iphone in Settings > Mail > Account, you have to enable Calendar on the Mail account on which the meeting invitation with the ics files is received.


How to reset gedit preferences?

Question: gedit lately suddenly started to open new files in new windows and it is really frustrating to me. I searched graphical preferences, preferences listed by How to change gedit preferences from terminal? and I also tried to uninstall gedit, remove all gedit files/folders in $HOME and reinstall gedit back, but nothing of that didn't help.
Comment: Uninstall needs to be a "purge" to remove personal settings ;)
Comment: I uninstall everything using purge, but in case of gedit it just didn't work. Maybe a bug?
Comment: What version of Ubuntu do you use? Is it clean install or upgrade?
Comment: Clean 18.04 Ubuntu
Answer: Gedit settings are saved in GSettings or DConf, so you can reset them with the following command:
<code>dconf reset -f /org/gnome/gedit/
</code>
Comment: Thank you, so my issue is a bug, this preferences reset also didn't help with initial problem...

How to reset gedit preferences?


When should I report multiple r-squared versus adjusted r-squared in a linear regression?

Question: I am trying to report the r-squared value for the results of a linear regression in R using the lm package. I noticed that the summary function provides two r-squared values for my equation: adjusted r-squard and multiple r-squared. In most of the analyses I have run the two values are identical, but in a small minority of results they give different values. Given this, I am trying to figure out in what situations I should report adjusted r-squared and which should I report multiple r-squared. It was my impression that one reports multiple r-squared if they have a multivariate regression, but I was not sure.
Comment: Report for what purpose? Why not give both? After all, `summary` in `R` gives both.
Answer: The short answer is that you should almost always report adjusted R-squared in favor of R-squared.
The long answer is that it depends and you have many more choices available than only R-squared and adjusted R-squared. I wrote a whole paper on this topic, see https://doi.org/10.1525/collabra.343. This answer provides a nice summary: https://stats.stackexchange.com/a/451772/30495


Changing Links in Page Viewer

Question: I currently have a page viewer on my SharePoint site. One of the links is outdated and needs to changed, is there a way to update/change the link without doing HTML?
Answer: What do you mean about "One of the links is outdated"? Where is the link? Is it a link display in the page viewer web part? Or it is the link of the page viewer web part?
If it is the link of the web part, you can edit the page viewer web part and directly change the link.

If it is the contents displaying in the web part, you can go to the source location to directly change the link.
(Page Viewer is the web part that displays another Web page on this Web page. The other Web page is presented in an IFrame.)
Comment: Hi, the link that is displayed in the page viewer is the web part itself. The webpage viewer is on the right side of my main page. It has content with 3 different bullet points and one of those bullet points links are outdated. How can I change the bullet point? Thanks! Sorry if I wasn't clear on the description.
Comment: Could you please provide some screenshots? What do you mean about "is the web part itself"? I think you need to go to the source page to edit the bullet point.

Changing Links in Page Viewer


Playing flash file on my DVD player

Question: I want to make my flash file to play on my dvd player. It has some scripted buttons on it, so it is important that this works, is it even possible to make a swf into a DVD format and then play it with scripted buttons?
Answer: As far as I know, there isn't any way to directly convert a flash movie with interactivity into a DVD menu.
The best you can do is to import the assets for the flash movie into some DVD authoring software and use that to build the interactivity that you need.
You will find that the DVD menu format has many limitations over what is possible with flash.

Playing flash file on my DVD player


How can I speed up minecraft after buying more RAM?

Question: My Acer C7 is running Chrubuntu. After I bought an 8GB ram extension, Minecraft is still running with only 5-9 fps. My system shows 9.4 Gigs of ram running, but this still makes no difference to Minecraft. I allocated more memory to Minecraft but this still didn't make any changes to the lag. Why is this?
Comment: How did you determine that RAM was the limiting factor? I would have thought the low-level onboard GPU (or possibly CPU) is much more likely causing the slow down...chromebooks aren't set up for gaming.
Comment: @Ash You might want to post something like that (with some rewording, and possibly expansion) as an answer.
Comment: hmm, I didn't even think about that. I wonder, is the mother board on my device capable of upgrades? I know this would void the crap on my warranty, but still. Any help?
Answer: I suspect the combination of low-powered CPU and graphics is causing the framerate issue, rather than RAM.
Adding extra RAM would help in situations where the machine is running out of memory. If it isn't, extra RAM will make zero difference to in-game performance.
One test would be to run top in a console while running Minecraft. If the CPU is hitting maximum (100% for single-core CPU, 200% for dual-core, etc), the CPU is probably causing (or contributing) to the low frame rate.
As far as I know the CPU in a C7 is going to be soldered onto the motherboard. Upgrade options are extremely limited (unless, as the commenters in that Tom's Hardware thread say, you're handy with a soldering iron).
Unfortunately, it's just not a gaming machine.


What does the "1:" before the package name mean in yum.log

Question: I would be very glad if someone could explain what the 1: before the package name signifies.
Answer: 1 is the RPM epoch number. It overrides the normal comparison order on version checking. So, if there is some odd reason why you as a packager want to mark a lower version number as an upgrade, you can tag it with an Epoch number.
yum info xorg-x11-xauth

Name        : xorg-x11-xauth
Arch        : x86_64
Epoch       : 1
Version     : 1.0.9
Release     : 1.el7
Size        : 30 k
Repo        : base/7/x86_64
Summary     : X.Org X11 X authority utilities
URL         : http://www.x.org
License     : MIT
Description : xauth is used to edit and display the authorization information
            : used in connecting to an X server.

Comment: I notice that not every package has an epoch number.
Comment: @Sajuuk more correctly, a missing epoch number is equal to `0`.


How long should a professional singer be able to sing in a single breath ?

Question: How many seconds of nonstop voice (or silence) without taking another breath is satisfactory for a professional singer ? Is there a rule thumb ? does it depend on  the register ?
Answer: You should be at least able to delay your breath in such way that it does not interrupt with your singing.  Being able to sing more is a big bonus, but we can't really put a value on that: Just as long as you can...
You shouldn't be trying to sing more than you are able to, as that will also interrupt with your singing.
Unless you are practicing of course, just make sure you are comfortable on a life performance... ;)
Lower registers need more breath pressure, so they need more breath to do the same.
However, people that need to sing high notes also need more breath for those notes.
But, unless you were to compare yourself with someone else, registers shouldn't really matter...
Comment: Trying to sing 'more than you are able' is generally not a bad idea, but there are a few exceptions, such as in *Annie Get Your Gun*: "I can sing any note longer than you.... Yes I caaaa........n".  If the vocalist is practically keeling over at the end of the note, that would add to the charm of the scene more than if the vocalist appeared to be capable of going for another 15 seconds.


Does Inkscape work with CMYK?

Question: Does Inkscape work with CMYK?
what is the color tab (picture)?
Comment: No. Inkscape is an SVG editor for on-screen graphics. It's RGB only. However you can export a design as a PDF from Inkscape, and then manually change the colours to CMYK using Scribus, which is also free and open source.
Comment: That reads suspiciously like an answer @BillyKerr `:)`
Comment: @Scott Yeah I suppose it is, although the answer is basically "No".  I've added it now.
Answer: You can see in Inkscape (and in GIMP, too) as one of the coloring options CMYK. It will show for ex. pure max. bright green RGB(0,255,0) as CMYK(100%, 0%, 100%, 0%) which is plausible.
It's also exact if you have a CMYK color producing mechanism which creates all sRGB colors with the simplest possible linear transformation.
But Inkscape cannot output CMYK color files, CMYK exists only as a color selection possibility. Even worse problem with Inkscape and CMYK is that Inkscape knows nothing of real CMYK printing.
One can find easily in document settings and program preferences some interesting dialogs, but they do nothing, they are still only beautiful dreams. An example:

The shown text Euroscale Coated v2 is the name of one generic CMYK printing color profile.
The transformation between normal on the screen RGB colors and printed CMYK colors is extremely complex, non-linear and depends strongly on the used print process and paper. Generally only a part of onscreen RGB colors are possible in usual CMYK printing processes.
That's one good reason why Adobe succeeds to collect high profits year after year. Adobe's programs know the conversion between real CMYK printable colors and the usual RGB. People select the right CMYK printing color profile into use and see on the screen what they will get from the printer. Programs also flag possible unprintable colors and help user's to avoid the printed muddy mess which would come out if one makes his design with bright RGB colors and transforms them to CMYK like Inkscape does, not by having the right CMYK print process color profile.
As said already in the other answer, Scribus understands CMYK print process color profiles and can help you to see the realistic result if you import your file to Scribus and convert it to CMYK.
Unfortunately it isn't available in the fly as you create a new design in Inkscape like a realistic result can be seen in Adobe's programs during the design. Edit: Not true! See the fixes at the end of the answer.
Krita is another freebie which knows realistic CMYK printing and can show the result during the design work. Serif Affinity series do the same with low cost.
Another useful idea would be to decide the color palette in a CMYK printing conscious program. The RGB conversions of those colors could be used in Inkscape and see the realistic result in the fly.
ADD in May 2022: GIMP 2.10 understands CMYK print profiles, it can show the CMYK printing result and can warn if something is unprintable in CMYK. This all is availabe in the real time when one edits his RGB image in GIMP. The actual conversion to CMYK must still be done outside GIMP, for ex. in Krita, if one wants to use Freeware.
Add in September 2022 If one has both Inkscape and Scribus properly installed, the Inkscape dialogs shown above start to work so that the CMYK printing result of the RGB drawing can be directly previewed. That's been said in another answer one and half an year ago. It doesn't work if the programs are executed as separated by some sandboxing system which prevents them to see each other.
Answer: No. Inkscape is an SVG editor for on-screen vector graphics. It's RGB only.
However you can export a design as a PDF from Inkscape, and then manually change the colours to CMYK using Scribus, which is also free and open source.
Answer: Yes, kind of - there's built-in Color management, built-in print preview and CMYK PDF export included with Inkscape. It requires Scribus to be installed, though, for this to work, and your file to be set up correctly.
More details are available at
https://wiki.inkscape.org/wiki/index.php/Release_notes/1.0.1#Color-managed_PDF_export_using_Scribus
Answer: The main problem of Scribus is that it looses the vectors after conversion to pdf, becaming useless for some professional printing, depending on the purpose.
Comment: This does not provide an answer to the question. Once you have sufficient [reputation](https://graphicdesign.stackexchange.com/help/whats-reputation) you will be able to [comment on any post](https://graphicdesign.stackexchange.com/help/privileges/comment); instead, [provide answers that don't require clarification from the asker](https://meta.stackexchange.com/questions/214173/why-do-i-need-50-reputation-to-comment-what-can-i-do-instead). - [From Review](/review/late-answers/113127)
Answer: The simplest way to convert pdf from inscape to CMYK is by using ghostscript. I did a batch file on Windows and just drag&drop pdf file on it in Explorer. The result isn't the best possible, but ghostscript allows us to use CMYK color profiles, so we can mess up with this and find the suitable result.

Does Inkscape work with CMYK?


How can I speed up my first few pages on a ddev Drupal 8 project?

Question: Drupal 8 is notoriously slow on the first page (like the install page) or the front page after a webserver starts up (including under ddev). Is there a way I can speed it up a bit? I think the problem is that all those thousands of Drupal php files have to be loaded into the opcache before it runs right. Is there a way to do that?
Answer: I'm experimenting with the brand new Composer-Preload package for this. It's fairly easy to get going with Drupal 8. The maintainer has been super responsive in improving it for compatibility with Drupal.
As suggested in the README:

composer require ayesh/composer-preload (or ddev composer require ayesh/composer-preload
Edit the composer.json to add the required section to "extra":

    "preload": {
        "paths": [
            "web"
        ],
            "exclude": [
               "web/core/tests",
           "web/core/lib/Drupal/Component/Assertion",
               "web/core/modules/simpletest",
               "web/core/modules/editor/src/Tests"
            ],
            "no-status-check": false
        }

run composer preload (or ddev composer preload). This creates the vendor/preload.php that does the actual preloading. It rummages through all the files in the listed directories to see what should be preloaded.
Link the preload.php into your docroot (or another directory reachable from the webserver). For example, is the docroot is "web", inside the web container (ddev ssh) do ln -s /var/www/html/vendor/preload.php /var/www/html/web/preload.php
If for ddev, add a curl command to run on ddev start in your .ddev/config.yaml:

hooks:
  post-start:
    - exec: curl -s localhost/preload.php

Your mileage may vary, but it seemed to me that my D8 project was much snappier to start with this setup. Thanks to @ayesh for the excellent Composer-Preload project, it has a great future.
Answer: Our solution has been to use APCu, which I recommend in production as well. Here's how we have DDEV setup -- also, I recommend disabling the Symfony APCClassLoader as it's deprecated and slower.
ddev/config.yaml
hooks:
  post-start:
  - exec: sudo apt-get update
  - exec: sudo apt-get install -y php-apcu

your settings.php
// Don't use Symfony's APCLoader. Composer's APCu loader has better performance.
$settings['class_loader_auto_detect'] = FALSE;

Comment: Thanks for the suggestions. But how can this affect initial startup? When you `ddev rm` and `ddev start` the php opcode cache is not primed, and first hit on a Drupal 8 page for example can take 15-30 seconds before you see the page. apcu doesn't have anything to do with opcode caching, and is only used for application-type  variable caching (like memcached).  So I'm confused how this would affect the scenario envisioned in this question.

BTW, if you put your two steps into one, you'll wait less for startup, `bash -c "sudo apt-get update && sudo apt-get upgrade -y`
Comment: And, of course, if you think php-apcu belongs inside the container we'll try to add it.
Comment: Oh and one more request... Could you update to mention that your settings.php mod is for Drupal 8?
Comment: And despite the above, my own experience bears this out as a great technique. Way faster. How can it be?
Comment: I guess what I was missing from your description was that the class loader performance is what gives this amazing benefit. I've added this recipe to https://github.com/drud/ddev/pull/1368, it will be in next ddev release, probably v1.6.0, mid January 2019.


Connecting to SSH with Fingerprint of the SSH Key

Question: Hello! I have problem with connecting to remote host. I forgot ssh password but I have Fingerprint of the SSH Key. Is it possible to connect with using just fingerprint?
Comment: Fingerprint of who's SSH key?
Answer: No.  The fingerprint of the machine is just used to verify you're connecting the machine your think you're connecting to.  It is public information used to avoid Man in the Middle Attacks (MITM) on your SSH session.


When is the time that Couchbase write documents to disk?

Question: As the title said, when is the time that Couchbase write documents to disk? every 60 seconds? every 1 seconds? every 100 ms? or everytime there are read command to that document?
Comment: Just to be clear, are you talking about the write from the managed cache, through the disk write queue to the persistence engine or much lower level of when things are flushed to disk from buffers?
Comment: I think both would be nice..
Answer: I will answer your question as I lay out the higher level flow objects take through Couchbase on their way to disk.

Object is written to the managed cache by the application
Simultaneously a pointer to that object is placed into a queue (Disk Write Queue) for the object to be persisted to the DB storage engine, currently called Couchstore. A pointer is also put into a replication queue to replicate that object to a replica, but that is another discussion.
Depending on server resources, namely disk write speed, the objects will then be moved to Couchstore. The disk write queue can grow quite large if the amount of incoming data is large and the disk are slow. This is an area that needs to be looked at as part of sizing a cluster. It is not just all about raw read/write speeds, but also how the queue is filling and draining. You want the disk fill and drain rates to be as close as possible and the disk write queue to be as close to 0 as you can get it. This is especially critical if you are going to be using PERSIST_TO style writes.
Once it gets to Couchstore, it is persisted to disk. There is some batching in there, 1000 per vBucket if I recall correctly. This is to improve performance. Also, while there is an OS buffer (I was incorrect in using that term before), Couchbase does not depend on it, but there is an fsync after each batch.

One thing to remember, pretty much all of this can be monitored using the Admin Rest API or looked at in the WebUI. These are all great candidates for being monitored on an ongoing basis if you care about performance.


How do I decide what the exact xpath is to find and open all profiles on a web page using Selenium and Python?

Question: I am new to programming, and I am trying to build a test software to automate the data retrieval from a website. I am, however, finding it difficult to define the xpath, so that all of the individual profiles can be found and clicked on.
'/html/body/div[1]/div[2]/div/div[3]/div/main/table[2]/tbody/tr/td/div/table/tbody/**tr[2]/td[1]**/div/table/tbody/tr/td[1]/a'
'/html/body/div[1]/div[2]/div/div[3]/div/main/table[2]/tbody/tr/td/div/table/tbody/**tr[2]/td[2]**/div/table/tbody/tr/td[1]/a'
'/html/body/div[1]/div[2]/div/div[3]/div/main/table[2]/tbody/tr/td/div/table/tbody/**tr[3]/td[1]**/div/table/tbody/tr/td[1]/a'

I am finding it difficult, because the variables are in the middle of the xpath and don't know how to write the profilesCount and the for loop.
Sorry, if my question sounds dumb, I have read all resources I could think of, but found no solution. Thank you for your help in advance.
Comment: Share the relevant html. You should also avoid absolute `xpath`, it's bad practice.
Comment: @nysse share the html page
Answer: tell me if I am wrong
if I got it right, you want to make a loop thats going to check all profiles on website .... If its the same problem as I had in my proxy_gatherer, then this solution may help you:
for x in range(2,34):
    try:
        u1 = browser.find_element_by_xpath('//*[@id="tbl_proxy_list"]/tbody[1]/tr[' + str(x) + ']/td[1]/abbr').text
        except:
            print('proxy out of range')

in your case ( based on all informations you provided ):
for x in range(2,last_profile_id):
    for xx in range(1,2):
        browser.find_element_by_xpath('/html/body/div[1]/div[2]/div/div[3]/div/main/table[2]/tbody/tr/td/div/table/tbody/**tr[{}]/td[{}]**/div/table/tbody/tr/td[1]/a'.format(x,xx))

explanation what i did:
based on xpaths you provided I analysed which parts are changing ... here it was :
// tr[2]/td[1] // -> its written bold here :

'/html/body/div[1]/div[2]/div/div[3]/div/main/table[2]/tbody/tr/td/div/table/tbody/tr[2]/td[1]/div/table/tbody/tr/td[1]/a'

I hope I helped you :) if no and I completely missunderstood what did you ask, please let me know ^^
Comment: StyleZ, thank you for your help. This did help me. :)


Savings settings in a custom PHP plugin for WordPress

Question: First, I'd like to pre-emptively apologize for doing anything naive or foolish. I'm a novice programmer, but I'm trying to learn. Right now, I'm trying to develop a plugin for wordpress as part of my internship. The plugin does what it needs to do for the most part, but I just can't seem to make the settings page work the way I want. I know the initialization part of the plugin is working properly, but I'm having trouble with using the settings page. Specifically, I don't where or how to use _POST in order to save the information. I also don't where to place the update_option function call after I've received the information from the settings page. Here's my code right now:
add_action( 'admin_menu', 'menu' );
add_action( 'admin_init', 'plugin_admin_init' );

function plugin_admin_init() { // whitelist options
  register_setting( 'plugin_options', 'plugin_options', 'plugin_options_validate' );
  add_settings_section('plugin_main', 'Main Settings', 'plugin_section_text',           'plugin');
  add_settings_field('plugin_text_string', 'REE View Count Settings',           'plugin_setting_string', 'plugin', 'plugin_main');
}

function menu() {
    add_options_page( 'REE View Count Options', 'REE View Count', 'manage_options',     'plugin', 'plugin_options_page' );
}

// generates the settings web page
function plugin_options_page() {
    echo '
';
    echo '
Options
';
    echo '<form action="' . $_SERVER['PHP_SELF'] . '" method="post">';
    // In the line above, I don't know what to put. The file name of the plugin?
    // The URL of the settings page on the admin page? Or what I have currently?
    // Both the first and last options bring up a 404 page.
    settings_fields('plugin_options');
    do_settings_sections('plugin');
    echo '<input name="Submit" type="submit" value="' . esc_attr_e('Save Changes') . '"         />';
    echo '</form>';
    //update_option('plugin_options', $_POST['plugin_options']);
    // Where should I try to update the option? And how?
    echo '
';
}

//from add_settings_section parameter 3, in plugin_admin_init
function plugin_section_text() {
    echo '
Main description of this section here.
';
}

//Function from 3 paramter of add_settings_field in plugin_admin_init that outputs     input HTML
function plugin_setting_string() {
    $options = get_option('plugin_options');
    echo 'value of options is: ' . $options;
    echo "<input id='plugin_text_string' name='plugin_options' size='40' type='text'
    value='{$options}' />";
}

//Validation function from register_setting in plugin_admin_init
function plugin_options_validate($input) {
    echo "this is input: " . $input;
    $newinput = trim($input);
    if(!preg_match('/^[0-9]+$/', $newinput)) {
        $newinput = 10;
    }
    update_option('plugin_options', $newinput);
    return $newinput;
}

Note: I don't actually use these exact function/variable names - I have them prefixed with the actual plugin name.
Can you help me? I want to take the information the admin inputs into the settings page and update the database with the that information (which in this case is just a single number). I understand that I need to use PHP _POST, but I don't know how. Furthermore, I don't where to post to, because when I use action="the_file_name.php," I get a 404 error upon submission. What should the action of the form be so that I can use the information that I got from the admin submission and use it for later? And after I do that, how do update the setting? And by how, I mean where do I place update_option? I apologize if this seems rambly or vague - I feel like I'm somewhat over my head.
If it helps, I've been building this settings page in the same file as the plugin itself, with the help of this guide: http://ottopress.com/2009/wordpress-settings-api-tutorial/
Unfortunately, I don't see anything in that guide that speaks of updating information, just creating the page itself.
Answer: You want to point to action="options.php".  It handles updating the values.  Check out the following links to get more detailed info.
http://planetozh.com/blog/2009/05/handling-plugins-options-in-wordpress-28-with-register_setting/
http://www.sitepoint.com/wordpress-options-panel/


What's the configuration of chromium(III) in aqueous medium according to crystal field theory?

Question: It has $\mathrm{3d^3}$ configuration, but how will we decide if they enter $\mathrm{t_{2g}}$ or $\mathrm{e_g}$ orbitals since we don't know which complex will form?
Comment: The amount of ligands that can fit  around a cation is guarded by sterical factors. The exact shape and spin of the complex formed is guarded by energy: a configuration with lowest energy is formed. (actually it is a bit more complex, read about kinetic and thermodinamic control)
Answer: You nailed it, this is almost a chicken-and-egg problem. As long as we don't know which complex will form, we cannot say which orbitals are populated. This is why it is often and regularly repeated that you need to know the geometry before you can make a call.
In an octahedral complex, the $\mathrm{t_{2g}}$ orbitals will always be populated first as they are lower in energy. (Look up any introduction on crystal field theory or check out the answers on this site.) In a tetrahedral complex, $\mathrm{e}$ — not $\mathrm{e_g}$, as there is no centre of symmetry, meaning the the $\mathrm{u/g}$ designators do not make sense, even though the orbitals are still often called $\mathrm{e_g}$ at introductory level — are the orbitals of choice to begin with. Again, just look at the scheme.
Thankfully, however, we can make an educated guess based on various factors.

octahedral complexes are more common especially at introductory levels and for the 'top middle' of the d block elements (roughly from titanium to nickel)
the LFSE (ligand field stabilisation enthalpy) can be calculated to $\pu{-12Dq}$ in the octahedral case and $\pu{-8Dq}$ in the tetrahedral case which twice prefers octahedral
there is no compelling reason (size or charge balance) to consider tetrahedral to be preferable to octahedral.

Thus, the complex you are looking at will most likely be octahedral — and so it is: it is hexaaquachromium(III) $\ce{[Cr(H2O)6]^3+}$, which is octahedral.
Comment: Btw, I think electronic spectra are good enough evidence that the complex is octahedral: since these have a centre of symmetry, the transitions are parity forbidden and tend to have extinction coefficients 1-2 orders of magnitude smaller than typical tetrahedral complexes. I'll see if I can find a spectrum
Comment: Yes, I didn't even go into spectroscopic details. That requires an experiment that OP maybe cannot make being restricted to paper chemistry.


Is Patty Mayo's Youtube content legal?

Question: I've recently been watching a youtuber by the name of "Patty Mayo". He arrests people who fail bond payments or fail to appear in court.
I've seen "Cops" before, but this guy doesn't blur faces and lists the fugitive's full name and on what charges they're being arrested for, as well as why they were supposed to appear in court in the first place. He also seems to goad confessions out of the fugitives for their original crimes. All on camera, obviously. His videos regularly have hundreds of thousands of views, sometimes going over a million or more.
He also uses the videos to promote his own merchandise, but I've noticed that he mutes the volume whenever his company name is said.
Is this legal? To me this seems like he directly profits off of destroying these people's reputations and uses his own job to (closest term I could find) "double dip".
He seems to do most of his work in LA.
Comment: Well, for starters, the fact that Mr. X has been ordered to appear in court on charges of Y, and did not do so, would typically be a matter of public record.  (That's probably how this bounty hunter found out about them in the first place.)  So revealing that could hardly violate any law.
Comment: Destroying someone's reputation with truthful information is perfectly legal.
Comment: @ohwilleke I'm wondering why doxing someone with information obtained from public sources is illegal in some places. Or is it?
Answer: If Mayo's content was against YouTube's Terms of Service, due to copyright, illegal activity or lack of model releases for the people filmed, I think by now Google would have taken his channel down due to complaints and Google's own housekeeping.

To me this seems like he directly profits off of destroying these
people's reputations...

What is happening is one or a combination of several of these things:

As NateEldrige pointed out in his comment to the question "the fact that Mr. X has been ordered to appear in court on charges of Y, and did not do so, would typically be a matter of public record. (That's probably how this bounty hunter found out about them in the first place.)" So revealing that could hardly violate any law. Public records for people wanted for bounty violations are public and are used to find them.

Video taping the general public is generally legal. See Law SE What is the definition of a "Public Space" for photography? and Wikipedia Photography and the law.

After the taping of a segment, it's possible all individuals are asked to sign a release allowing the use of the video. See Is it legal for police to travel with a film crew and publicize arrest footage without consent? - Law Stack Exchange. If they don't sign, he can't use the tape.

There are some sites on the web that claim that (some or all of) Patty Mayo's videos actually use paid actors to recreate bounty hunter and arrest incidents, and as such the videos are not "real."

As for

He also uses the videos to promote his own merchandise, but I've
noticed that he mutes the volume whenever his company name is said.

This may be a result of Google's TOS and restriction on advertising or use of his business name in his channel; it's hard to say without knowing details.
Comment: Many bounty hunters are self-employed, in which case "double dipping" wouldn't be an issue. Also, if he is employed, his employers are surely aware of his channel and could have fired him if they objected.
Comment: Taping in private is not legal, and you don't have a right to tape people who AREN'T on the warrant in their homes. (read: family members). The show is fake. See my other comment. The Oregon Sheriffs have talked with Mr Mayo and directly state the entire show is a SHOW and all people are paid actors.
Comment: @KatasticVoyage Whether it's legal to tape in private depends on jurisdiction.  If you are making such a claim you should clarify the jurisdiction and ideally provide some sort of reference.
Answer: Another issue not discussed is that he is technically making a "Citizens' Arrest" which is a lawful arrest by a non-deputized citizen of a person who is breaking the law.  In Common Law districts such as the United States, Citizens' Arrests are legal provided that the person who is subject to the arrest is treated in a legal fashion by the person arresting them.  The videos may also serve as evidence that Patty Mayo's arrests are legal and that any claims of abuse made by the detained are demonstrably false.  Typically police agencies do take a dim view on Citizens Arrests due to how easy it is for a lay person to cause the arrested individual harm.  In effect, putting these arrests up on youtube.
The muting of certain portions is related to California wiretapping and photography laws.  In CA, filming without permission is not a crime if it is conducted on public property.  You do not need to ask anyone permission to film them.  However, recording a conversation between a group of individuals in public if the individual is not making public statements does need consent of all parties (even if they are making statements to the film crew only... that needs a signed waiver).  This doesn't count if the activity is clearly meant for the consumption of the public, such as the chanting of protesters, the testimony in a local government hearing, or the rando-crazy person yelling that you need to repent because the end is nigh.
Answer: He isn't a real bounty hunter. The people that he apprehends are actors that can be booked through talent websites. He is doing this for entertainment purposes only.
Proofs:
https://youtu.be/9IgS8cnP-YQ
https://youtu.be/2c2oi9caq7U
Comment: Please give citations for your claims. No matter how true they may be, evidence is needed to back them up.
Comment: This is absolutely fake according to the Oregon State Police's official announcement on the show.

https://oregonsheriffs.org/youtuber-patty-mayo-is-not-affiliated-with-oregon-sheriffs-offices/

".Mr. Mayo is not a member of law enforcement, nor affiliated in any way with any Sheriff's Office in Oregon. He is an actor and the uniform he wears is a costume.  [...] production crew or paid actors/actresses.  Sheriff's Office has met with Mr. Mayo and advised him filming his videos in public locations cannot continue without the proper security, permits (if needed) and road closures"
Answer: Destroying someone's reputation with perfectly legal information falls under a civil tort of invasion of privacy. Invasion of privacy is included in our constitution as argued by Chief Justice Douglas "the constitution included "penumbral rights of privacy and repose." Simply put hes risking an attack on his wallet with his 15 minutes of fame on youtube.
Comment: The question doesn't appear to describe "intrusion of solitude", "public disclosure of private facts", "false light", or "appropriation". These are the four categories of invasion of privacy. False light would require proving malice.

Is Patty Mayo's Youtube content legal?


How to debug Web2py applications?

Question: Is it possible?
By debug I mean setting breakpoints, inspect values and advance step by step.
Comment: The title says win2py, and the tag says web2py.  Can you correct one of them?
Answer: You can do remote debugging of python web apps over TCP/IP with winpdb.
(Link appears down as of June 2019. Try PyPI winpdb)
Comment: Link          broken ____
Answer: I haven't used web2py, but if it runs in a terminal window, you can use standard pdb stuff. Add this line somewhere in your code:
import pdb; pdb.set_trace()

This will invoke the debugger and break.  Then you can use PDB commands: n to step to the next line, l to list code, s to step into a function, p to print values, etc.
Answer: One can debug applications built on Web2py using the following set-up:

Eclipse IDE
Install Pydev into Eclipse
Set Breakpoints on your code as needed
Within Eclipse right-click the file web2py.py and select Debug As -> Python Run
When a breakpoint is hit Eclipse will jump to the breakpoint where you can inspect variables and step thru the code
Answer: You can also use Visual Studio 2010.  Here's how:

Download and install Python Tools for Visual Studio.
Create a new project from existing code (File > New > Project From Existing Code...)
Specify your web2py folder and use the defaults.
Right-click on web2py.py and choose Set as Startup File.
Set breakpoints and hit F5 (run) or right-click on web2py.py and choose Start with Debugging.

This is a nice setup if you already use visual studio.
Answer: Yes, it is possible, Due to the "span prevention" I am still not allowed to post screenshots, but here is a full screenshot hosted at my website:
http://static.techfuel.net/debug_web2py.png
Answer: I'm debugging web2py applications with Eclipse and PyDev. Here is an article:
http://www.web2pyslices.com/main/slices/take_slice/2
Answer: As Carl stated, it is as easy as:

Installing PyDev in Eclipse
Right Click on your Web2Py project, selecting Debug As > Python Run
Selecting web2py.py as the file to run

No other plugins or downloads are needed.
Answer: Here is an article on debugging python with pdb, which will work with web2py. http://sontek.net/debugging-python-with-pdb
Answer: @Ned Batchelder is almost right, but the standard way of doing it in web2py is slightly different.
Instead of `import pdb; pdb.set_trace(), you use the code:
from gluon.debug import dbg
dbg.set_trace()

When executing the web application, the application will freeze when it reaches this section of code.  You then go to http://127.0.0.1:8000/admin/debug/interact (using the root URL for your application) and it will show a fully interactive, web based debugger:

See documentation.

How to debug Web2py applications?


How do you transfer between three eagles?

Question: My last achievement is to transfer between three eagles as Bing Sven.
How do you do it?
Comment: Could you tell us what you've already tried?
Comment: Tried starting with an eagle from the cabin. Then flying at cloud level to the next eagle but they're hard to catch.
Answer: The main thing to realise here is that you don't have to catch the next eagle in the air.
Once on the ground avoid other animals until you can catch the next eagle.
Comment: This worked, achievement unlocked
Answer: First of all, many people think that this is like bat transfer and you can exchange eagles in air ... This is absolutely wrong.
The fact here that if you land from the eagle, you can ski for some distance and ride an eagle again (Just try to avoid animals in the way) and also hitting obstacles when you are skiing doesn't reset the challenge.
Here's the thing: You will have 2 main problems:

Finding an Eagle
Catching an Eagle

First of all: Begin with the Eagle as the starting animal and activate super Eagle then start flying (Hitting obstacles while you fly resets the mission but hitting obstacles while skiing doesn't reset it).
You should fly in air in horizontal level or cloud level. After the lifetime of the Eagle ends you should now have an eagle in front of you and an eagle behind you. Catching the one in front of you is very hard so you should bury your head in the snow several times until the eagle behind you re-appears. Now it's your chance catch him.
Here are some tips for catching:

Never flip while in air, you will never catch him.
Adjust your landing style (Let him lean forward not backward) i.e: Don't press on the screen while flying
At some points Eagles can be caught on ground, make use of this critical chance.
You will be very lucky, if you catched the second eagle before landing from the first eagle. (Make use of this levels)
At some critical points, you will be facing the Eagle just infront of you but it will be faster (Use the super blue boost which can be bought from the shop)
When you use the blue boost, use it on the third eagle not the second because the third one is always hard and needs the blue boost.

I have been three hours doing this sh*t and it was my last challenge and finally did it, hope you guys do it too. You won't succeed from the first time. It's just a matter of trial and error. You will restart and restart and restart until you do it. Hoped I helped :)
Answer: I followed the directions on this forum post
In summary: To setup turn off super eagle, select Eagle Bluffs, and select the eagle as your starting animal. Then, from the home screen, wait for an eagle to fly by before pressing the ski button. You'll start out with one eagle and then quickly transfer to the second eagle. Getting the third is tricky, hopefully you can catch one after a hill or two. If not, just avoid all other animals until the third eagle. Just keep going back to the start of the game until it works.
Answer: Since no one here knows how the easiest way is , here it is, Once you start the level wait for an eagle to show up before you hit go or whatever, then try to hit the first eagle right out at the gate, immediately after you hit him hit the pause button and return to the main menu.  ( You have gotten 1 eagle already) then redo the same steps 3 times.