How can i jump to game development and continue career in 7 months?

Question: How can i jump to game development and continue career in 7 months?
Comment: 7 months is not that much, i daubt you're going to learn what you have to in this amount of time. You'd probably want to spend half of that getting better at just english if you want to move to the US, where you are now is not going to cut it. If you want a job as a game developer, the most important thing is that you make games. If you have a C# background then you could either try making something with XNA or move to Java and try developing something for the Android. Also C++ is hard to master and games require you to master it. You can't assume you're "just going to learn it".
Comment: Maybe its better not to be fixed to a career as game developer. Why don't you try to get indie? Program games in your spare time. When they're good enough you'll find someone who makes neat graphics for them. Therefore you don't need to live in a extreme wealthy country to do this.
Comment: This question does not have a *correct* answer. GDSE isn't for discussion based questions. I think you knew that before posting it since you say that people can give you downvotes as long as you get answer.
Comment: @DonCarleone Please see the [FAQ](http://gamedev.stackexchange.com/faq#etiquette) about etiquette. Thanks and good luck with your career, your people skills will come in handy!
Comment: @DonCarleone What makes you think I down voted the answer? It has two down votes, one person can't down vote twice. You don't know who down voted, so don't attack me (or anyone else). People down vote an answer if it's not useful. I imagine down voting this answer would be because it's impossible to answer your question correctly, so pretty much any answer to it is not useful. It's not a personal thing, please, calm down and don't take these things personally. Please practice good etiquette or don't post.
Answer: Before trying to switch your career to game development you should get some experience on actually making games. I don't believe any company would hire a game programmer without any game programming experience even as a junior.
This may sound hard. How can you get the experience if you can't get a job in the industry? You should start by programming games on your free time or by studying game development in a school. There is also the possibility of starting as an independent game developer, but it doesn't pay you any salary until you succeed.


Is the output from a 120V 300W UPS enough to kill a person?

Question: I recently got an old APC BK300 UPS  (Input:120VAC & Output:120VAC 300W) along with many other  vintage electronics stuffs. So I tried opening the the UPS completely.I noticed that the battery a 12V 7Ah BB battery SLA was completely dead. Well I kinda added som edistilled water and revived it and it seems to be working fine now after a day of charging with a high power automotive charger and put it back on the UPS after resealing the SLA. I removed the UPS buzzer since it was kinda annoying. Connected the SLA and powered up the UPS and connected a 130V 100W bulb and it was glowing bright.I usually do some power electronics stuffs from mains and having been looking to replace the mains as source with an inverter or UPS(always feared getting electrocuted). So does a UPS has enough juice to kill me like power from mains 110V outlet? Also there are two transformers inside the UPS a really big one and a small one on the circuit board.Which one is the inverter transformer? I've posted some pics below.
Comment: The UPS puts out the same thing the outlet does.  You can be electrocuted by the outlet, so you can be electrocutedby the UPS.
Comment: I guess, enough to kill not just one person.
Comment: A few mA can kill you. This will definitely kill you if you're not careful and take basic precautions.
Comment: estimates are ~5ma through the heart to kill you, that's a mere 0.6W.. so......
Comment: Which makes me wonder... do standard UPS units include ELCBs in their outputs? I do see a site wiring fault indicator there but that may not be the same thing.
Comment: Guess I better get some rubber gloves. Plus those caps inside might be holding some nasty charge I guess.
Answer: SHORT ANSWER: YES! Also be careful handling the circuit board even when its not plugged in. The capacitors can shock you!
I would bet that the small transformer is there for the small electronics that control the annoying speaker you removed (step down transformer) and the big one is simply for safety and is for the inverter. (Isolation transformer)
LONGER ANSWER: 120 VAC from any wall socket alone will shock you and can kill you. Although there is the debate of "volt vs amps" being more lethal, its known that amperages between .1 and .2 amps (100 or 200 mili-amps) will kill you. That UPS is can put out a whole 2.5 amps which is roughly 100 times more than the lethal amount
Formula: power = (voltage * amperage)...
so solving for amperage is...
Amperage =( 300 watts / 120volts ) which is 2.5 amps
The big tansformer is probably an isolation transformer. Its there to keep you from drawing more than 2.5 amps in case of a short. the little one is there to get the voltage down to something suitable for a voltage regulator to manage for the logic circuits that control the UPS. (5 volts maybe)
Comment: I agree with you mate. If it can light a 100W bulb then its got the juice but the only reason I asked this noob question was because this was from a battery source. The 110V mains usually gives in 10-15Amps easily.
Answer: Killing you is not that hard. You don't have to be burned to charcoal state for that. Enough stopping your heart by 60Hz voltage.


raise the minimum reputation required for downvote

Question: As the title suggests, I would like to hear everyone's opinion on who should be allowed to downvote. I have seen youngsters downvote good answers simply because they could not understand it. They should instead request a clearer explanation rather than downvoting. What do you think ? Should the reputation for downvote be increased?
Comment: You can't see "youngsters" downvote "good answers simply because they could not understand it" because votes are anonymous and "good answer" is obviously subjective. You can find a multitude of discussions about downvotes [on meta.SE](http://meta.stackexchange.com/questions/tagged/down-votes) and well as [on this meta](http://meta.physics.stackexchange.com/questions/tagged/down-votes). It's not clear to me what raising the reputation is supposed to do, and I'm not under the impression we suffer from people downvoting *too much*.
Comment: Can you provide some examples? From my experience, I have seen *many* bad posts being upvoted, but near-to-zero good posts being downvoted. Also, you don't know who cast the votes, so they migjt come frpm youngsters or from knowledgeable users who see clear errors in the posts
Comment: i agree,  but should'nt there be sufficient justification for downvoting as well? some of the new guys probably get discouraged when they see their answers downvoted.
Comment: knowledgeable people would have no problem reaching the required reputation for downvoting within a month.
Comment: (As an aside, [voting is different on meta](http://physics.stackexchange.com/help/whats-meta); in this case downvotes probably mean disagreement with your premises or proposal rather than an opinion that the question is 'bad'.)
Comment: NOTE: I only gave 1 reason so far, but i'm sure many of you would have seen other reasons.
Comment: am i wrong there?
Comment: The important part is that you don't know how is downvoting, so you don't know if changing the whole privilege system would have any impact at all
Comment: On my opinion, only very few downs is coming from this reason. In general, there are few downs on the PSE. The problems of the site have total different reason. You shouldn't worry on the downs, there are quite different reasons to worry.
Comment: *"Should the reputation for downvote be increased?"* For anonymous votes (up, down, etc) without stating the reason, I think the reputation for voting must approach to infinity.
Answer: Let's examine the facts: according to the last data available, only 705 users with reputation between 125 and 250 had casted any downvote (out of 4065). From them, only 33 had casted 10 or more downvotes. Yes, there is an exceptional case, but the rest seems perfectly normal.
In addition, you don't know what posts did these users voted (because votes are secret!!!), you don't know their motives, and you don't know whether these users are in fact knowledgeable new users. You don't really know anything about downvotes, but you're proposing to change the whole system based in your prejudices.
In the technical part, the privilege system isn't controlled by the Physics.SE site, it is a part of the SE engine. In order to propose a change, you have to go to mother meta. And believe me, you will need much stronger arguments.
Comment: all right then. I'll leave it here for now.
Comment: It's also important to note that the exceptional case you note is not a novice SE user; s/he has ~15k rep on web apps and used to have ~40k on maths.se before s/he deleted that account. You can argue all you want about why that person acts that way (or you could, you know, ask them), but I think it's pretty far from a youngster dragging down stuff they don't understand.
Answer: Yes, this can be a problem, but as Bosoeando showed in his answer, with one exception, it's a very small problem. Keep in mind that the cure to a small problem is oftentimes worse than the disease.
Moreover, the biggest areas where this could be a problem have already been addressed. One potential problem is serial down-voting, which is mostly committed by users with a low reputation. The SE software automatically detects and corrects most of these serial voting problems.
Another potential problem is questions that have made the SE hot list. These hot questions are an open invitation to people from elsewhere on the SE network to join the site. The problem was that users with a high enough reputation elsewhere on the SE network receive 100 points just for signing up with another element of the network. The solution is to quickly mark these hot questions as protected. Newbies who receive those freebie 100 reputation points cannot vote, up or down, on protected questions.
Comment: No, that last bit is not quite it. With the 100-rep association bonus you can upvote, but you need 125 rep to downvote. Protecting a question only stops people posting answers (and requires 10 rep earned on the site, independently of the association bonus) but it doesn't stop you from voting. Newcomers from other parts of the network coming here via HNQ with only their association bonus can vote up but not down by default, and protection only stops them from posting.
Comment: While I do agree that HNQs are more likely to need protection than other questions, I don't agree that pre-emptively protecting all of them is a useful solution to anything.


How many times can I refresh the 90-day stay in Taiwan? Can I keep refreshing it with a visa run indefinitely?

Question: As a UK citizen I understand I can spend 90 days visa-free in Taiwan and extend this by a further 90 days, after this can I keep doing visa runs to get additional 90 day stays?
Comment: Why do you want to spend so long in Taiwan? Extension requests can be denied if the purpose of stay is unclear https://www.boca.gov.tw/dl-1941-10818f41fd244cbbbb5de39737fc963a.html
Answer: Not really. This is a thing of the 1990s, not the 2020s. This is now very much frowned upon by just every country in the region (except, maybe, the PRC). Staying 90 days, leaving, and coming back the next day is tantamount to living there without a resident visa, not paying taxes, etc.
While this used to be tolerated 30 years ago, it's not today. It shows also in the tourist visa extension scheme: you get a measly 15 days, not another full ride – as is the case for instance in Thailand. They do not want you to stay much longer as a tourist. Trying a visa run might get you the "no extension will be granted" stamp too.
Another complication is the visa run itself. Most places around Taiwan will not let you fly to Taiwan on a TPE-somewhere return ticket and no resident visa. If you can't show them either a resident visa or a plane ticket leaving Taiwan, they won't let you board the flight to Taipei. In case you were denied entry in Taiwan they'd be held financially and legally responsible, something airlines do not particularly enjoy.
Even as an older business exec, who can't be suspected at first sight of being a "digital nomad" I was systematically asked for a visa or onward ticket in most of Asia's airports. The most insistent/anally retentive being Japan, South Korea, Taiwan, Vietnam and HK. In places like Thailand, Laos or Myanmar it was kinda random.
Your best bet is to enrol for Chinese classes, and get a student visa. Be sure to attend the classes, Immigration tends to check attendance records.


Of web service implementation

Question: I am trying to implement a small, very flexible REST web service. I've done it in the past, but I didn't like the approach and I still don't like. How can one parse the query variables in a more elegant way ? Doing things like:
if query_variable in uri: do_things_based_on_query_variable
look fairly ugly to me, especially when all of those query variables map back to a database.
Can someone give an example of how an Web Service is implemented ? I am interested mostly in Python Web Services and how they're handled in the controller implementation.
Answer: Have you looked at Routes?

Of web service implementation


How to turn the contact rings in an empty fluorescent bulb socket from closed to open?

Question: A fluorescent bulb was improperly removed from its sockets. I am unable to turn the contact rings from the closed to the open position. I would be thankful for any advice.
Comment: I stick a bulb in pins at the contacts and rotate. Some tombstones will snap into position and feel like they will break before releasing. Wiggle both CW and back CCW and it should release even if the lamp is not totally square with the fixture.
Comment: I just had exactly this problem. While attempting to remove the bulb, I experienced a large amount of friction while trying rotating, so instead I popped out the bulb. I didn't expect to end up in this situation. I used a voltmeter to verify the on/off state, and then used needle-nosed pliers to rotate the plastic 90° back in a controlled manner. In the process, a chunk of plastic broke off; maybe it was catching. My tip: when rotating the bulb back in, make sure both sockets stay flush against the bulb, otherwise the prongs might pop out, and you must repeat the process.
Answer: Those black pieces are meant to turn 360 degrees in any direction.  You already have a key to turn them, in the form of a fluorescent tube.  Keep the tube as close as possible to its proper position (i.e. don't try to do this at much of an angle).  Turn off fixture power.
Worse come to worst, if you break the lampholder (aka tombstone) or if that type just annoys you (they annoy me), new lampholders are fairly standard, common and cheap.  I typically pay 60 cents each for them and keep a bagful on hand. You can mix and match types though I prefer to keep "circular" types separate from "v" types.  Height is also a factor, they come in 3 heights.  Yours looks like a medium.  You don't want a short but a long will probably suffice.
Comment: Thanks for your time and detailed advice, Wolf. The pins on the tube were bending too much, so I used the backs of two small wooden paint brushes to turn the contacts to open. Looks like I've saved a buck twenty for now.


my black garlic cooking in a rice cooker went brown and hard before black any ideas?

Question: I have my garlic in the skins in a rice cooker on the warming setting after 7 days the garlic was brown dried out and hard, is it over cooked and not slowly caramelized?  what is the purpose of putting it on a steaming tray? there is a vent hole in the lid of my cooker should I cover it up with plastic wrap not allowing steam to escape? Any ideas?  I'm starting a new batch and I will cover that vent hole to see what happens.
Answer: To make black garlic, you're trying to break down the sugars in the garlic. It sounds like you're dehydrating it, rather than giving it time for the enzymes in there to do their work. You need to somehow prevent the moisture from escaping. Covering the vent hole may be sufficient, but I'd suggest putting the garlic is in an airtight container to be sure - perhaps wrap it tightly in plastic wrap to keep the moisture in there. Once the sugars have converted, you could then unwrap it for a little while to dry out the skin further if you liked.
There's an interesting article that talks a bit about what's going on inside black garlic here
Comment: Hmmm...I had similar results to the OPs when I tried to make black garlic in a rice cooker. She's not clear if she broke up the cloves, I didn't. Maybe I'll dry vacuum sealing it if I try again.
Answer: I've been making black garlic in the rice cooker successfully  by wrapping a bundle of cloves twice with tin foil, I also close the vent of the cooker and put some glad wrap around the lid, mine take around 14 days to get black but still very moist so I just unwrap and leave in the cooker unsealed until they dry out a bit


Can't get rid of hyperlapse flickering on post-processing after using Lightroom and LRTimelapse

Question: I have a Sony A7C with the basic Sony FE 28-60mm F4-5.6 lens, and I went to one of the 3 best places in the world to see the night sky. I tried to shoot a night sky hyperlapse using the interval shooting function.
I set the camera mode to Manual, with manual focus, 4000 ISO, f/4, 28mm focal length and 4 seconds of shutter speed.
Since it was my first time trying this mode, I didn't expect one of the worst enemies of hyperlapses: flickering. I then started researching how to deal with this in post-processing and I tried using the trial version of LRTimelapse.
The workflow I used is as follows: I imported the sequence to LRT and computed a first visual preview, then saved metadata, switched to Lightroom to read the metadata and started with colour-correcting the first image as the keyframe to apply it to all the images. I used the following settings for the post-production:

I then switched back to LRT, reloaded the metadata from Lightroom and computed the visual preview again to see the amount of flickering. I then started to deflicker setting 30 as smoothing, high precision and a multi-pass deflicker of 3. Since the initial flickering was abnormal, as shown by the red curve in the following image. I had to improve the deflicker 3 times to kill all the flickering according to the magenta curve:

Now, in this image, I also tried to select a subset of the photo, but the final result is the same as when I didn't use any subset, and the flickering is so high that the clip is unusable, as shown in this video, despite the curve is flat according to the smoothness. I also saw that not only my clip was suffering from exposure flickering, but also all the frames have visibly different colour tones.
Preview video from LRTimelapse
I researched then why this was happening and on the internet, I found who was blaming the dehaze function, and who was blaming highlights and shadows, but none of the attempts worked to minimise this problem. Also, the flickering was already visible from the raw images, but as far as I searched, the Sony A7C doesn't have an inbuilt deflicker.
Can someone suggest to me what I may have done wrong either in the shooting session or in post-processing?
Answer: If auto white balance was used that can/will cause a shift in color between images; and that can affect the exposure as well. But that should be easy to identify and rectify in the raw files (tempt/tint settings).
Long exposure noise reduction could also be having an affect; it does apply to raw files as well, but I would expect it to be much more subtle
I don't see any other setting that would/should affect the raw files.
Have you tried the TimeLapse DeFlicker program? It has a free trial version you could test on the problematic scene.


'LocalLibrary' file

Question: I'm looking to add a large number of words to my spell checker lexicon. I've been told to go to Library > Spelling > LocalLibrary, but there is no such file in my Spelling folder (or anywhere else on the computer). There is only 'dynamic-counts.dat', 'dynamic-text-tmp.dat', and 'dynamic-text.dat'. I'm on a MacBook Pro, Mojave 10.14.1. Is there another way of adding a batch of words?
Answer: It's called LocalDictionary not Library & is just a plain text file, but has no .txt extension.
I also have two others, called en and en_GB. I really don't know what the difference is, but they all contain different custom word lists.
Presumably, if there isn't one there already, you just need to create one.
If you don't want the task of doing that yourself, then right click any word the regular spellcheck doesn't like & 'Learn Spelling' - I'm pretty sure that should create the file & populate it with your first word.
One thing to note, if you're going the DIY route for this - words are in alphabetical order, not just added by date to the next line.
Comment: Oops, you're right, thanks. Even so, there doesn't appear to be a 'LocalDictionary' either, and clicking 'Add to Dictionary' for an unknown word in a Word document doesn't create any new files. The 'dynamic-text' files seem to be filled with words that I changed back from their autosuggestions in Safari. What extension would I have to use to create a LocalLibrary file? Just use a plain text file?
Comment: MS Word will use its own structure, not Apple's. I'm afraid I don't know much about Office at all, so can't help in finding that, sorry.
Answer: You can try /usr/share/dict/words maybe append your list of words to that file.

'LocalLibrary' file


How do I benchmark research if there is no previous work against which I can compare it?

Question: I'm working on a paper that there is no previous paper for it to distinguish. its an old tool like ant colony optimization that is used on a new approach. I have sent the paper to a journal and they have said it doesn't have a good benchmark.
Comment: Please clarify the question; is your paper about an old software that you adapted to use in a new problem?
Comment: yes more or less @MFornari
Answer: A benchmark is a standard or reference that will allow other authors compare their algorithms with yours. If the problem is known and other papers were published to solve it, follow the lead and compare your algorithm with them using the same parameters. If there are no other paper solving the problem, look for similar problems and check how they are described by certain variables.
The most basic parameter is the problem size, ie how many instances your problem has to deal with. For sorting algorithms, it is the number of items to sort. Usually, we start with quantities that could be easily handled in memory, increase to the limits of available memory, up to numbers that will need disk to store all items.
The second parameter is distribution. Are all instances equally probable and distributed along the possible spectrum? For sorting algorithms, if the set of items is partially sorted or totally random will impact the performance. In my thesis, I worked with geographical objects like cities, which are concentrated in some areas that were difficult to process, and other areas totally empty that could be easily recognized and discarded as not interesting.
Each problem might have multiple parameters, some are important, others are irrelevant. Your work is to identify them and choose values that are realistic and could show the strengths and weakness for different algorithms, not only yours.
Another set of parameters, very common when comparing software, is related to hardware, like the number of processors, total memory, network speed, etc...
Hope it helps, without reading your paper is hard to be specific.
Comment: my paper is about using ant colony optimization to find path like players and choose path like them. ant colony basically is used to find nearest path. so I'm using same tool on new application or approach. it works in way palyers add fromone to path instead of bots or ... in my tests it works but there is no same work
Comment: @virtouso Are you saying that no papers have approached that problem before in any way?
Comment: @TobiasKildetoft at least I couldn't find any thing on ieee Elsevier ....
Comment: @virtouso Then it seems like a bigger problem than finding an appropriate benchmark might be to justify why the problem is even worth looking at in the first place.
Comment: @TobiasKildetoft so can you tell me how can I include all of these to make paper be accepted? I just explained it in my paper but they mentioned a problem as: there is no good benchmark or enhancement
Answer: As others have noted, it is very difficult to know how to act or suggest when we have no idea of the full picture. However, the problem seems to lie on the fact that you are attempting to use/adapt a method to apply on a particular problem, and there doesn't seem to be a benchmark solution to the problem you are trying to solve.
One way to gauge your work with respect to the literature is to also solve a well-known problem that has an established solution in addition to your problem. However, if you have already established that there is no benchmark, then there is nothing you can do about it.
Perhaps one of the reasons why they (the reviewers, I assume) want a benchmark is because they want you to prove that your paper is of value. Comparing the method to a benchmark is one of the ways that can be done. For instance, value can be proved by showing that your algorithm is faster/requires less computational power/finds better local optima/etc than someone else's. However, if there is no benchmark, you may want to look for other ways of displaying the value of your paper. For instance, one way to do that is to show that the method allows you to understand certain so far unknown features of the problem (there are other methods to accomplish this goal, but that utterly depends on your problem/field/goal). However, while I don't know your field nor the people nor the problem, simply applying a different method to solve a problem that has been solved by other methods may not provide sufficient novelty to yield publication, hence why they probably want you to show value.
On the other hand, maybe they want some sort of validation that your code/method is actually working properly, which is a very common supplement provided in many numerical papers. If that's what they want, you can apply your method to a different problem that has a benchmark, well-established solution, and show that you can reproduce the results.
Finally, it may just well be that you are trying to publish in the wrong venue. If you are trying to publish in the "Journal of Methods that Require Comparison to Benchmark Solutions", then you are probably out of scope.


Are there any economists in history that contributed to the language of mathematics?

Question: As it is known that math as a branch that is disputed whether it is a science or a language, I am just curious whether there is an economist that contributed to mathematics as a branch (I am not talking about the implementation of mathematics to economics), as Newton invented calculus (I know Leibniz as well) to solve the physical problems and several instances of physicist contributed to Math can be observed as well.
Comment: Depending on how big a contribution you count, the answer is obviously yes. There are a lot of economists with PhDs in economics working in economics departments who have publications in mathematics.
Comment: Hi @Tunay. Probably someone polymathematical like von Neumann who made important contributions to economics (and is often called an economist, accordingly). Most of his contributions are in pure math, but he of course would draw on these for computer science, economics, etc. There are potentially more scholars than vNM. But I couldn't think of anyone else off the top of my head
Answer: We can mention John Maynard Keynes and  Frank Plumpton Ramsey, in the field of the theory of probability. In particular, their contributions are considered important with regard to the subjective theory of probability.
Subjective theory of probability was developed mainly by the mathematicians Bruno De Finetti and Leonard J. Savage, as opposed to the frequentist and to the classical theories of probability.
Keynes published, in 1921,  his A Treatise on Probability.
Even if Keynes' theory of probability is important also with regard to economics, and the relevant matter of expectations in economic theory, the Treatise on probability is a true text of pure mathematics, or better, Keynes would have said, of logic, as he considered the theory of probability as a part of logic.
Keynes is an advocate of the subjective view of probability and criticized the frequentist approach which, neglecting  the unique event as extraneous to science, and in general situations that cannot be traced back to classes of events,  excludes from the domain of probability problems that are typical of situations of uncertainty:

"The identification of the probability with statistical  frequency
is a very grave departure from the established
use of the word; for it clearly excludes a great number of judgments,
which are generally believed to deal with probability.$^1$

Distancing himself from frequentism, Keynes outlined a 'logicist' conception of probability, considered as 'rational belief' and expressed by a logical relation between two statements:

We seek to justify some degree of rationale belief about all sort of
conclusions. We do this by perceiving certain logical relations
between the premises and the conclusions. The kind of rational
belief we infer in this manner is termed probable (or in the limit
certain), and the logical relations, by the perception of which it is obtained, we term relation of probability.$^2$

$$***$$
Ramsey also, who was a mathematician, a philosopher and an economist, is considered a proposer of the subjective theory of probability.  His most well-known work about probability is Truth and Probability (1926)$^3$.
Ramsey proposed a  subjective theory of probability as a measure of the degree of partial belief of an individual before alternatives options. $^4$
But he maintained  a different perspective with respect to Keynes , and he wrote in 1922 a review of Keynes' Treatise, 'MR Keynes on probability', where he criticizes Keynes' concepts of logical probability-relations and non-numerical probabilities.$^5$
Ramsey is well-known also as a pioneer of the theory of decision in conditions of uncertainty, and for his studies in combinatorics, in particular he is famous for the so-called Ramsey Theory, and a generalization of the Pigeonhole Principle.
$$***$$
The French mathematician Émile Borel also devoted an article to Keynes' Treatise, in his Traité du calcul de probabilité et ses applications (1924-34), distancing himself from Keynes:

Borel and Keynes were the contemporaries who crossing over the English
channel, greatly influenced each other in the twentieth century. In
his influential book, Borel (1938) harshly criticized Keynes' position
on probability theory. In plain English, Borel regarded probability as
a measurable object, thus constituting one important branch of
mathematics. In contrast, Keynes thought of probability as a
non-measurable item, thereby belonging rather to one branch of logic.
Their controversies were rather well-known in the academic world,
producing so many papers even after their deaths until today.$^6$

$^1$  Keynes, John M., A Treatise on Probability, Wildside Press, 2010, p. 105
$^2$ ibid. , p. 123.
$^3$  Ramsey F.P. (1926) Truth and Probability, lecture at Moral Science Club, Cambridge; published for the first time in Ramsey F.P. (edited by Braithwaite R.B.) (1931),The Foundations of Mathematics and other Logical Essays, Kegan Paul, Trench, Trubner & Co., London.

$^4$ Ramsey  F.P. , 'Probability and partial belief', https://www.repository.cam.ac.uk/items/74959b5f-c87f-4bfe-b723-96877693f882
$^5$Ramsey, F. P.1922, [1989], 'Mr. Keynes on Probability', The Cambridge Magazine, vol. 11
, 3–5. Reprinted in British Journal for the Philosophy of Science, vol. 40, 219–222.
https://www.journals.uchicago.edu/doi/abs/10.1093/bjps/40.2.219

$^6$ Yasuhiro Sakai, 'Émile Borel Versus John Maynard Keynes: The Two Opposing Views on Probability

Answer: The following are some contributions.

Game Theory: Perhaps the most well known field of mathematics to which economists have made significant contributions is Game Theory (if it is not considered a branch of Economics itself.... so much is the value of Economists' contributions....). The founders of this field are John von Neumann and Oskar Morgenstern. von Neumann was a polymath and is considered an economist as well. Morgenstern was primarily an economist by profession. They founded the discipline with their analysis of zero sum games. Many concepts of choice within the set of equilibria, such as Schelling points were developed by economists. A lot of equilibrium concepts were developed by economists, in fact, too many to mention. The entire sub-field of studying games of incomplete information was pioneered by economist John Harsanyi. Reinhard Selten developed the concept of sub-game perfect equilibria and other concepts to study extended form games. The development of Mechanism Design also owes a lot to economists like Leonid Hurwicz, Eric Maskin and Roger Myerson, who received their Nobel Memorial Prize for the same.

Linear Programming: Leonid Kantorovich and Tjalling Koopmans made significant contributions to linear programming. Both received the 1975 Nobel Memorial Prize in Economics. While Kantorovich had formal training in mathematics, he is widely credited as an economist as well. Kantorovich's approach to resource planning is foundational and he is credited as one of the founders of Linear Programming. He discovered that coefficients in linear programming problems can be essentially interpreted as prices. You can watch Fields Medalist Cedric Villani's lecture where he also discussed Kantorovich's work. Koopmans had formal training in Economics under Jan Tinbergen, first winner of the Economics Nobel, in addition to training in mathematics and physics. One of Koopman's major contributions include the determination of optimality conditions in linear programming problems.

Statistics and Probability Theory: Economists have obviously contributed majorly to Econometrics, and thus, to many parts of Statistics and Probability Theory that are relevant to Econometrics. The Matrix formulation of the Linear Regression Model was developed by economists like Ragnar Frisch, in addition to statisticians like Fisher. Frisch, along with Frederick Waugh and Michael Lovell, also contributed to a geometric understanding of regression, for example, in the Frisch-Waugh-Lovell theorem. Trygve Haavelmo has contributed to the development of the theory of maximum likelihood, structural models etc. Economists have contributed to the development of numerous estimators. For example, the development of the theory of the Generalised Method of Moments owes much to economists like Lars Peter Hansen. Economists like Lawrence Klein l, Robert Engle and Granger have made highly influential contributions to times series analysis such as cointegration and Granger causality. Statistical approaches to the study of causality owes a lot to economists such as Josh Angrist and Guido Imbens, who used Rubin's model to go beyond the "correlation is not causation" idea.

Decision Theory: Decision theory is closely related to microeconomics and has applications to philosophy and logic,statistics, computer science and even quantum mechanics. Several foundational results in this field have been given by economists. While the concept of utility was propounded by philosophers like Bentham and Mill, economist Alfred Marshall formalised it. Later, Ragnar Frisch laid the foundations of the Theory of Ordinal Utility using binary preference relations. This was developed further by economists like Arrow and Debreu who developed the Theory of Rational Choice and Social Choice. Paul Samuelson, an American economist, developed the logically equivalent theory of Revealed Preference. In a parallel stream, von Neumann and Morgen Stern's work led to the development of the Theory of Cardinal Utility. All of these are foundational to the field, in addition to the work of statisticians and mathematicians, like the Savage Axioms.

Many of these contributions are often considered parts of Economics itself, while in other contexts, they will be considered distinct. For example, Game Theory is often taught as part of Microeconomics, but it has applications in Computer Science, Biology, Political Science etc. as well. Similarly, Decision Theory is almost inseparable from Rational Choice Theory, which is at the heart of Microeconomics. But you would see this topic discussed in detail in other places independent of Economics, such as in Philosophy or Statistics books. Take the example of this entry from the Stanford Encyclopedia of Philosophy on Expected Utility or this entry on Decision Theory. The topics mentioned for Statistics and Probability are also often rightly taught as part of Econometrics, but they are also taught in other academic fields.
Thus, it is often difficult to separate results by discipline, especially when two of the disciplines concerned are as diverse and wide a field as Economics and Mathematics. For an interesting conversation on this, you can see this interview of Economics Nobel Laureate Amartya Sen, where he describes how many a times what is considered interdisciplinary can be thought of as a part of one's own discipline or vice versa, when asked why he chose to combine Economics and Philosophy. This happens in the cases of other disciplines as well. For example, as you mentioned Physics, Newton considered geometry and calculus to be parts of Physics (see pages 51 to 59 here).


In responsive design, where to show related content?

Question: I have a question that I would like your help with. I am creating a responsive website with readable content that has an 'In this page' section and 'Related content' section. Is there a best practice or a pattern to show these two sections in mobile? Thanks in advance for any advice give.
Comment: Would the reader want to access "In this page" before or after reading the main content?
Answer: Assuming, that the «in this page» section contains a short description of the content of this actual page (maybe even with anchor links) this section should definitivly be in the beginning of the page. Reason: This gives the user a short introduction and makes it easier to decide for the user if she is on the right page. Having this section at the end would nod provide any benefit since the user already scrolled through the whole content.
Releated content on the other side is something that can be accessed via other means like navigation or overview pages etc. So (again assuming) the related content section is not a navigational element but meant to provide further content that has to do with the actual content the user is already interested in. Related content should therefore be at the end of the content. This way the user has the possibility to access this content without having to go back to navigation.
What you could do (if the «in this page» section is anchor links) is to have a linkt that goes directly to the «related topics» section.
Answer: After the main content. Always.
You can't relate things to nothing, things are related to a main object, so the main object should be the first thing your users see. This question is very easy to test: just visit any blog or e-commerce site and you will see that the related content is in the only logical place, which is AFTER the content it refers to.
If you mean only those 2 sections in the sidebar, the answer is the same, but the explanation is different: one of the elements explicitly says "in this page", which means that the content in that section is related to the page the user is reading.
The other section is an extension of the information for people who need or want to know more about the topic and/or related topics, but it is NOT the topic itself, just an addition.
Finally, from a structural point of view, it's usually the stacking order for most pages in desktop, and in your example it certainly is, so you shouldn't do anything special, it will follow the natural stacking order without any problems


Bitcoin core wallet

Question: Can anyone point me in the right direction I downloaded the bitcoin core qt wallet wee while back all the files that come with it are everywhere not in the right path I don't know much about this there's a lot of files just don't know what to do with them would anyone have a idea for someone who knows where little about it which would be the easiest way to generate a new wallet to something that would be simple for me to use and what files to look out for some of the ones I've seen is a about rsa key,files about generating keys,wallet hash tree I think it was pools and stuff I've just no idea thanks
Answer:
all the files that come with it are everywhere not in the right path [...] there's a lot of files just don't know what to do with them

What you wrote suggests you downloaded the source files. If I wanted to do this I'd follow guidance at https://www.google.com/search?q=build+bitcoin+core+from+source but I suspect you are not comfortable with this, so instead ...
I suggest you download the single-file precompiled-installer for your operating system from https://bitcoincore.org/en/download/ and run that.
Comment: Thank you for your reply I went onto it thats where I got my new wallet I downloaded that to see what to look for, for my old wallet to remember I thought I could transfer it over or generate that into my old wallet

Bitcoin core wallet


Is it mandatory for non muslims to wear a skull cap when they enter a mosque for visiting and during namaz to join the namaz service?

Question: Is it mandatory for non muslims to wear a skull cap when they enter a mosque for visiting and during namaz to join the namaz service.
Comment: Caps are not mandatory for men. Just make sure that you don't wear shorts.
Comment: As salam Aleikhum my friend it will be the first time I will be going to a mosque. I am talking about males is it mandatory for males even non muslim males to wear the cap I hope my question is clear this time.
Comment: Do I wear the cap out of choice  I am talking about dress code for males.
Answer: I guess you refer to something like this?
Well a cap is not necessary to enter a mosque it is even not mandatory -for a Muslim (men)- to pray, but it is recommended. I've even know that (at least some) tablighis spread ahadith (plural of hadith, prophetic traditions)  who strongly recommend having a head cover for men and practice this, but most of these narrations have weaknesses.
The strongest argument for doing or practicing this however is what one may call good taste and to show some kind of respect for your creator in front of whom you are going to pray and whom's "House (of worship)" you are visiting...
On the whole there are many questions already on the site on that topic which you might check:
- Is it obligatory for Muslim men to cover their heads while praying?
- What is a reliable reference for "covering of the head during salah or otherwise is mubah" by men?
- Headcovering For Men in Islam - Required?
...
And somewhat relevant (parts of my answer on): Was Quran 24:31 changed? "...believing women ... should draw their khimar over their breasts..."
The most important thing if you go to pray in a mosque is that you cover your 'awrah, this means for a men you should wear at least something that covers the body between the knees and naval, however covering your shoulders etc. is strongly recommended based on ahadith.


How to compute ElGamal decryption by hand

Question: Lets say that $u=3, x=5, v=2$, how do we work out $u^{-x}*v$, so $3^{-5} * 2$. I know how to work out the answer if it was $3^5 * 2$ but how do we do it with negative exponents?
Comment: I added some formatting to your post - Please ensure I did not change the meaning (I had to assume the precedence for u^-x * v was $u^{-x} * v$ and not $u^{-x * v}$)
Answer: We're not trying to compute $3^{-5}\ast 2$, but instead we're trying to compute $3^{-5}\ast 2\mod p$ for some prime $p$.
This is notation for $(3^{-1})^5\ast 2\mod p$, so if we can compute what $3^{-1}\mod p$ is, you can just plug that value in and do computations like you'd expect.
Note that $3^{-1}\mod p$ means the element $u\in(\mathbb{Z}/p\mathbb{Z})^\times$ such that $u\ast 3\equiv 1\mod p$.
For example, because $2\ast 2\mod 3 \equiv 1\mod 3$, we have that $2^{-1} \mod 3= 2$.
Or, because $2\ast 3\equiv 1\mod 5$, we have that $2^{-1}\mod 5\equiv 3$.
The quantity $u^{-1}$ ends up being uniquely defined (when it exists --- $2\ast 3\equiv 0\mod 6$ means that $2^{-1}\mod 6$ can't exist), but note that it depends on both $u$ and $p$.
A computationally inefficient (but conceptually simple) way to compute $3^{-1}$ is via Fermat's Little Theorem, which states that:

If $a\in\mathbb{Z}$, then $a^p\equiv a\mod p$

If $a\neq 0$, this is equivalent to $a^{p-1}\equiv 1\mod p$, and therefore $a^{p-2}\equiv a^{-1}\mod p$.
So we can compute $3^{-1}\mod p\equiv 3^{p-2}\mod p$, which you can do by hand.
If $p$ is large this might be annoying, but there are some tricks to speed it up (known as exponentiation by squaring).
A more computationally efficient way to compute this quantity is the Extended Euclidean Algorithm. This requires more explanation though, and if you want to know more about it you can probably find some resources online explaining it (it's a standard topic in elementary number theory courses).


Ubuntu Single Sign On

Question: I wanted to backup my data before I proceeded to upgrading my Ubuntu, which requires you to login into the Ubuntu Single Sign On, however I am unable to recollect my password. Trying to use the forget password option, gives me an invalid email address. However if I use the same email  for registering as a new user, it gives me as a registered email address, preventing me for registering using the same email. Can you please help?
Comment: You can use offline or manual back-up solutions instead of whatever you're trying to use. If you keep your data on a separate partition from the system files, you don't even need to back them up, because they'll be left untouched during the system installation or upgrade.
Answer: Sorry File services on ubuntu One is discontinued.

Send an email to isd-support asking for a password reset.
Then find somewhere else to upload your image, you can create an account at MEGA
https://mega.co.nz/#
Then create account. Or find somewhere else USB device DVDs for your backup.

Ubuntu Single Sign On


Newey West standard errors give me more significance

Question: I had a time series model with 5 time series variables and it's a model that's reputed in the literature for having autocorrelation problems. Why when I use standard OLS var-covar matrix only 2 variables are (highly) significant but with Newey West varcovar matrix 4 of the variables are (highly) significant (1% level)?
Answer: There may be several effects. First, you may be hitting negative autocorrelations somewhere down the road. Second, most sandwich-like estimators are biased down, so with short samples (say of total length 10-15), you may have notably larger biases with the smaller data set.
If there are wild swings in significance, you need to proceed conservatively: report both, but act only on the evidence that's supported in both specifications.
Comment: I have 1000 time series observations and it's my HAC Newey West that is giving me significance across the board (you said they were "biased down"? Or did you mean SEs were biased down and not the test statistic?)
Comment: The standard errors are biased down. $n=1000$ should not give you trouble. Look at the ACF/PACFs to see if you can spot any negative autocorrelations of the residuals. May be your model is simply misspecified, and then there is little you can do about it other than adding some extra terms, lags, etc.


What's the difference between a body corporate and a corporation sole?

Question: One of those instances where unfortunately there's not much to expand in this question apart from what's in the title.
Answer: A body corporate is another name for a company
Companies incorporated under the Companies Act or a foreign company.
This definition is particular to the UK - in other jurisdictions it is more widely defined to be synonymous with legal person and in others it can be even narrower than in the UK
A corporation sole is a legal person that is embodied in a particular individual
They are most commonly found in ecclesiastical and government officers to enable continuity and a smooth transition of assets, liabilities, and power when the holders of the office change.
So, for example, the Chancellor of the Exchequer is a corporation sole. When you want to sue the treasury, you file suit against the Chancellor. At present, the current Chancellor is Jeremy Hunt (although, UK politics being what they are this may have changed by the time I post this). Jeremy is the Chancellor but only for so long as he holds the position, the Chancellor as corporation sole continues to exist no matter who has the role or even if it is temporarily empty.


RealWorld HazelCast

Question: Does anyone have any real world experience with Hazelcast distributed data grid and execution product?  How has it worked for you?  It has an astonishingly simple API and functionality that seems almost to good to be true for such a simple to use tool.  I have done some very simple apps and it seems to work as advertised so far.  So here I am looking for the real world 'reality check'.  Thank you.
Answer: We've been using it in production since version 1.8+, using mainly the distributed locking feature. It works great, we've found a couple of workarounds/bugs, but those were fixed relatively fast.
With 1.8M locks per day we found no problems so far.
I recommend start using version 18.104.22.168.
Answer: There are still some issues still with its development,
http://code.google.com/p/hazelcast/issues/list
Generally, you can choose to either let it use its own multicast algorithm or specify your own ip's. We've tried it in a LAN environment and it works pretty well. Performance wise it's not bad but the monitoring tool didn't work very well as it failed to update most of the time. If you can live with the current issues then by all mean go for it. I would use it with caution but it's a great working tool IMHO.
Update:
We've been using Hazelcast for a few months now and it's working very well. The settings are relatively easy to set up and with the new updates, are comprehensive enough to customize even small things like the number of threads allowed in read/write operations.
Answer: We are using Hazelcast (22.214.171.124 now) in production integrated with a complicated transactional service.  It was added to alleviate immediate database throughput issues.  We have discovered that we frequently have to stop it bringing down all transaction services for at least an hour.  We are running clients in superclient mode because it is the only option that even remotely meets our performance requirements (about 4 times faster than native clients.)  Unfortunately stopping a superclient node causes split brain issues and causes the grid to lose records, forcing a complete shutdown of services.  We have been trying to make this product work for us for almost a full year now, and even paid to have 2 hazelcast reps flown in to help.  They were unable to produce a solution, but were able to let us know that we were probably doing it wrong.  In their opinion it should work better but it was pretty much a wasted trip.
At this point we are on the hook for over 6 figures per year in licensing fees and we are currently using about 5 times the resources to keep the grid alive and meet our performance needs than we would be using with a clustered and optimized database stack.  This was absolutely the wrong decision for us.
This product is killing us off.  Use with caution, sparingly, and only for simple services.
Comment: The old [what did you see](http://qph.is.quoracdn.net/main-qimg-2776209b9d9d72eef92d0910e8c72e13) joke
Comment: Did you resolve this?  Did you isolate the problem, or move to another technology?  What are the licensing fees you mentioned?  The core of azelcast is free, I thought.
Comment: @james, given that this answer was given a long time ago, what is the current situation of Hazelcast. Were you able solve your issues with the newer releases or did you work with some other solution. Would be interesting to know.
Answer: If my own company and projects count as real world, here's my experience. I wanted to get as close to eliminating external (disk) storage in favor of limitless and persistent "RAM". For starters that eliminates CRUD plumbing which sometimes makes up to 90% of the so-called "middle tier". There are other benefits. Since RAM is your "database" you don't need any complex caches or HTTP session replication (which in turn eliminates ugly sticky session technique).
I believe RAM is the future and Hazelcast has everything to be an in-memory database: queries, transactions, etc. So I wrote a mini-framework abstracting it: to load data from the persistent storage (I can plugin anything that can store BLOBs - the fastest turned out to be MySQL). It is too long to explain why I didn't like Hazelcast's built-in persistence support. It's rather generic and rudimentary. They should remove it. It is not rocket science to implement your own distributed and optimized write-behind and write-through. Took me a week.
Everything was fine until I started performance-testing. Queries are slow - after all of the optimizations I did: indexes, Portable serialization, explicit comparators, etc. A simple "greater than" query on an indexed field takes 30 seconds on the set of 60K of 1K records (map entries). I believe Hazelcast team did everything they could. As much as I hate to say it, Java collections are still slow compared to super-optimized C++ code normal databases use. There are some open-source Java projects that address that. However at this time query persistence is unacceptable. It should be instant on a single local instance. It is an in-memory technology after all.
I switched to Mongo for the database, however left Hazelcast for shared runtime data - namely sessions. Once they improve query performance I'll switch back.
Comment: *A simple "greater than" query on an indexed field takes 30 seconds on the set of 60K of 1K records (map entries).* This data is so unrealistically wrong, that it should raise a flag during any decent performance analysis. It looks so horrible, that I would ask questions like: "Why so many people use it then?" / Why are so many performance tests on the net discussing millisecond latencies and 100k inserts per second thresholds?" In the end I would start questioning the validity of my own test.
Comment: I am evaluating Ignite (http://apacheignite.readme.io/docs/overview) now. It has the same features as Hazelcast - at least those I need. I'll let you know in a week.
Answer: If you have alternatives to hazelcast maybe look at these first. We have it in running production mode and it is still quite buggy, just check out the open issues.
However, the integration with Spring, Hibernate etc. is quite nice and the setup is really easy :)
Answer: We use Hazelcast in our e-commerce application to make sure that our inventory is consistent.
We use extensive use of distributed locking to make sure SKU Items of inventory are modified in atomic way because there are hundred of nodes in our web application cluster that operates concurrently on these items.
Also, we use distributed map for caching purpose which are shared across all the nodes. Since scaling node in Hazelcast is so simple and it utilises all its CPU core, it gives added advantage over redis or any other caching framework.
Answer: We are using Hazelcast from last 3 years in our e-commerce application to make sure availability (supply & demand) is consistent, atomic, available & scalable.
We are using IMap (distributed map) to cache the data and Entry Processor for read & write operations to do fast in-memory operations on IMap without you having to worry about locks.

RealWorld HazelCast


Cannot reach obb expansion file on android 10 device if apk and obb is downloaded from Google Play store

Question: I looked for solutions from many places (Test programmatically if in Android 10+ the legacy external storage access is disabled, https://developer.android.com/google/play/expansion-files.html#Downloading, etc.), but don't know the exact cause of the error.
If app is downloaded from Google Play only in case for android 10 devices, it gives this error:
Caused by: java.lang.IllegalArgumentException: Couldn't get OBB info for /storage/emulated/0/Android/obb/packageName/main.package_version.packageName.obb

The program can find the obb file (even on android 10 devices)
File mainFile = new File(Environment.getExternalStorageDirectory() + "/Android/obb/" + packageName + "/" + "main." + packageVersion + "." + packageName + ".obb")

mainFile.getAbsolutpath()

gets the file path too. However, when Storage Manager is used for app that is downloaded from Google Play store
sm.mountObb(mainFile.getAbsolutePath(), null, mainObbStateChangeListener );

it cannot reach obb expansion file and terminates app with above error.
App can be downloaded from Google Play, but works only for android 9 or below devices. If I create apk and install it on android 10 device, the app can reach obb file without any problem.
What do I miss to be able run app on android 10 devices when it is downloaded from Google Play store? Help would be appreciated.
Update:
I found the cause of the error on Android 10 device, though I still don't know the answer:
If the apk version code (the version code in app gradle) matches to the version code in the obb file name (which it should be if I understood well (https://developer.android.com/google/play/expansion-files), then in the obbexpansionmanager class, the line
sm.mountObb(mainFile.getAbsolutePath(), null, mainObbStateChangeListener );

throws this error:
Caused by: java.lang.IllegalArgumentException: Couldn't get OBB info for /storage/emulated/0/Android/obb/packageName/main.package_version.packageName.obb.

If I change the downloaded app's obb file to a different version code (tested with version code 8, 1, 10 when apk's version code was 9) then app starts and above error does not come up. However, I cannot use different version code in the obb file's name other than the apk's version code to be able to download apk with obb from Google Play store. Furthermore, the media files cannot be reached from obb file unless it matches version codes.
If the device is under Android 10 then app works with same version code in apk and in obb expansion file.
Answer: A substitute method can be used instead of Environment.getExternalStorageDirectory() which is Context.getObbDir() which will return the full path of the OBB directory meant for the running application, i.e.: /storage/emulated/0/Android/obb/packageName.
This can replace the code part Environment.getExternalStorageDirectory() + "/Android/obb/" + packageName. More details of this method can be found here.
Comment: I got the same path with context.getObbDir(), but it's still not working. I made a work around, renaming the obb file when it wants to get obb info and when needs media files from obb file then I rename back to original name. Not nice, but this works for me


What does "bar against"mean?

Question: Administrative court complaints are however barred against decisions
[administrative acts] whose subject- matter is that of internal or external security of
the State … as well as other matters of foreign affairs. The decision of the [Federal
Ministry to refuse Nada's request for the removal of his name from the administrative
act freezing assets] refers to measures for the implementation of international
sanctions and belongs thus to those decisions dealing with matters of foreign
affairs for which the Federal Council [the Executive] has in principle [exclusive]
competence.
Answer: I don't think "barred against" is a structure here.
I think the text is saying that
"Administrative court complaints against decisions whose subject matter is xxx are barred."

What does "bar against"mean?


Gedit bash highlight

Question: When I edit bash script(first line is #!/bin/bash) in GEdit, there is no highlighting. But with View->Highlight Mode, there is no result when searching "bash" or "script", which to choose?
Comment: @ user68186 That doesn't work for my Ubuntu. The key seems to be the extension. When I remove .txt, gedit will treat it as bash even it is not executable. As a Windows user, I generally add txt to all generic files in Ubuntu.
Comment: Why do you not want to use the `.sh` suffix for scripts instead of `.txt`? There's no harm in having descriptive extensions.
Comment: @Justice for Monica Currently the file is a text file that I used to pass data between Windows host and Ubuntu VM, and this time I pass and edit a script. Will create a .sh for that.
Comment: The first time you save the file, the synthax highlighting will become in effect.
Answer: In gedit there is no bash or script highlighting mode.  The closest that they have is the sh highlight mode.
Plaintext mode:

View -> Highlight Mode -> sh then select:

sh highlight mode selected:

Gedit bash highlight


How to run magic commands in Jupyter deployed on Watson Studio?

Question: I'm trying to analyze my datasets on DB2 on Cloud in the Jupyter notebook created in Watson Studio. When using the "%sql" magic for connecting DB2 doesn't work naturally, showing no such module. According to an IBM tutorial, it is required to run the "%run db2re.ipynb" command in a Jupyter cell before connecting DB2. But when I run this cell nothing happens and the "%sql" magic still not available. Any advise is appreciated.
Comment: To which tutorial are you referring?
Comment: @data_henrik https://www.youtube.com/watch?v=bNfH0Wzx3is
Comment: Do you have that "db2re.ipynb" installed in your Watson Studio environment?
Comment: BTW: You can use that specific Db2 sql magic or this more general one: https://github.com/catherinedevlin/ipython-sql
Comment: @data_henrik Hi there, I'm not sure how to install it to my environment. I have it uploaded to the "Asset".
Answer: In general, there are two ways of accessing libraries in Watson Studio:
 - Install or import a library, then reference it. Note that you need to specify the --user option.
 - First save your own scripts, then import them.
There are also the built-in line and cell magics.
With that, I think I got it to work the following way:
1st cell, download db2re.ipynb to your environment:
%%sh
wget https://raw.githubusercontent.com/DB2-Samples/Db2re/master/db2re.ipynb

2nd cell, install necessary library:
!pip install --user qgrid

3rd cell, run the db2re.ipynb notebook extension:
%run db2re.ipynb

Thereafter, I was able to run a %sqlcommand.
Comment: Thank you very much for such detailed instructions!


Does RAM timings with n-n-n-3n value perform better than anything else?

Question: I want to ask something:
Does RAM timings with n-n-n-3n (i.e. 8-8-8-24, 9-9-9-27, etc) perform better or is optimized more than the other who doesn't (i.e. 7-8-7-21, 9-9-9-24, etc)?
Answer: Both the long and short answers yield the same thing:  no.
While you may believe by intuition that multiples of eachother would cause better system performance, this is not the case.  Those timing numbers simply represent the timing delay (in nanoseconds) of various operations for the memory to perform.  In every single case, you want these numbers to be as low as possible.
The lower the numbers are, the faster the RAM performs, and thus, the more operations and bandwidth can be performed per unit time.  At the same frequency, 8-7-8-20 will outperform (albeit not much more) memory running at 8-8-8-24.  If you compare these propagation delays to the time between CPU cycles, you will find that the RAM is always slower, and thus, the limiting factor.
For example, if you have a 2 GHz processor, the time between cycles is only 0.5 nanoseconds.  As you can infer from this, obviously you want the fastest possible RAM.  There is no advantage to matching the various timings as multiples of each other.
Answer: Essentially, the lower the memory timings, the better.
Of course, there are other variables that affect performance, like memory channel configuration (dual/triple channel). Also, if they're all not similarly matched specs-wise, I believe they will downgrade and match themselves to the lowest-spec module.
Answer: Theoretically, yes. However, in practice, you probably won't be able to notice a difference unless you know you are bottlenecked by the memory. Most of the time the storage device is the slowest part (hard drives especially), not the memory speed or latency.
In addition, higher bandwidth memory is usually better than lower latency memory, unless the bandwidth is limited by the memory controller (eg. i7 900 is limited to 1066 by default; motherboard manufacturers might allow higher frequencies with or without overclocking).
I wouldn't bother with anything other than DDR2 800MHz CL6 or DDR3 800MHz CL9, unless it runs at stock voltage (1.8V for DDR2, 1.5V for DDR3) and costs about the same.
Comment: This answer is wrong.  Faster timings are always faster, and there is no sense in recommending 800 MHz RAM when there is much faster RAM with tighter timings available.
Comment: @cp2141 Low quality flags are **NOT** for incorrect answers. They are to be used for answers that are too short, or thank you's. Moderators do **NOT** intervene in wrong answers, the community and voting takes care of that.
Comment: @cp2141, sure they are faster, but can you actually notice the difference between 6 and 4ns timings? There are other areas that will grant a much larger improvement in performance. No point in getting anything than the standard 1.8V DDR2 800 or 1.5V 1333, unless everything else is maxed out and you KNOW that the memory is the bottleneck.
Comment: I'm not doubting whether or not it's worth the extra money for tighter timings, but you allude the readers to believe the n-n-n-3n RAM is faster then ANY other combination.  Otherwise, why did you write "Theoretically, yes."...?
Comment: @cp2141: "However, in practice, you probably won't be able to notice a difference...". RAM is the fastest component in a computer; 3% or so improvement in throughput/latency won't matter when it's already too fast.
Answer: Modern CPUs have enormous caches. For typical software, the cache hit rate is around 90% to 95% (and sometimes as high as 99%). Improvements in memory timing will have a very small effect overall.
Trust me, I know this from measurements I made for several different types of programs. I made a memory cache performance analysis tool a few years ago that uses the CPUs performance counter registers. Free tools exist if you want to prove it for yourself (cachegrind).
If you care about stability more than a couple of percent of performance, go for less aggressively timed memory. You will have less issues with it and it will probably last until you don't want it anymore.


Scale F-curve from time/ 3D cursor

Question: A while ago I saw a demo where the f-curve could be scaled from a specific point in the time line - if I remember correctly determined by the 3D cursor - but I have not been able to recreate it. What I want to do is scale the points along the X-axis from a certain start frame. The default behavior seems to be the scaling is always from the middle which is not helpful in my case. Any ideas what I am missing?
Comment: Change pivot.. Used here - http://blender.stackexchange.com/questions/40334/how-do-i-alter-keyframes-for-a-new-framerate
Comment: @Patdog Please don't add "Solved" in the title. Wait for someone to post an answer or write an answer yourself. If your question was a duplicate, mark it as duplicate.
Answer:
I overlooked the 'hidden' menu, obscured by my small window. With thanks to Mr Zak for pointing out the 'change pivot', and my discovery of the 2D cursor.

Scale F-curve from time/ 3D cursor


How to interpret XIRR?

Question: I'm trying to calculate an investment's rate of return but getting very strange results. I made 6 different example scenarios to understand the logic behind XIRR calculation and just to test the results. In some cases I got the error messages and in the other cases just strange results.
Can anyone explain what I'm doing wrong?
Answer: XIRR is an annualized return, meaning the return for that time period if the same return were earned for an entire year. Therefore, it needs to know the time period between transactions in order to annualize the returns.
For #2: XIRR requires transactions to happen on different days. Your transactions happen on the same day, so there is no time period for which to calculate "return". (Theoretically, the periodic return is infinite since the transactions happen at the same time).
For #3: A 10% actual return over 31 days is much better than a 10% actual return over 365 days, which is reflected in XIRR. If you annualized the 31-day 10% return (meaning earned 10% every 31 days for a year), you'd get <code>(1+0.1)^(365/31) - 1 = 207.16%</code>
For #4 - there is no IRR where you gain 10$ in one month then "lose" another $300 the next month on a $100 investment. But, you didn't really "lose" $300 since you presumably still hold the stock, and it has value. One solution would be to put the "current" value of the stock as a "transaction" on the current date.  That would be interpreted as "what would the return be if I sold everything today at its current value".
For #5: You made 60% in two months, which is an incredibly high return when annualized (again, XIRR assumes that you make the same return for an entire year, which is not always realistic). As a side question, how did you get dividends if you sold the shares the month before?
For #6: Like #4, I would add the current value as a final "transaction" (otherwise it looks like you have to pay an additional $110 to exit the position, which is hopefully not the case).
Comment: It is said that XIRR is good for calculating a stock portfolio performance because it accounts for the depositing/withdrawal of funds over time. But what about day-traders who often make many trades a day? If XIRR requires transactions to happen on different days, then it is useless. And even for big fund managers we cannot be sure that some trades doesn't occur on the same day. How can they prevent such cases or is the usage of XIRR meant for very limited cases?
Comment: I would say that IRR is not good for day traders _if you're looking at individual trades_. You _could_ use it at the portfolio level if you aggregate all cashflows by day. If you're looking at individual trades with just an inflow and an outflow, then IRR is too blunt of a tool, since you can easily calculate the return for that trade and annualize it if necessary.
Comment: In other words, use IRR at the portfolio level but just straight (or annualized) return at the individual trade level.

How to interpret XIRR?


How to do texture modification

Question: I am working on iphone opengl es. I am a newbie to this. Can any one guide me how to proceed..
Answer: First, start with: Apple - Drawing with OpenGL ES. Then GLSprite and The Red Book.
After that, these are very handy: Lessens from Molecules, Apple Technical notes and Khronos - OpenGL ES Reference.
Answer: I would suggest you start with Apple's example code.  The GLSprite example might be a good place to start.
For general Open GL programming, the red book is a great learning guide as well.

How to do texture modification


How did my new iPhone know my WiFi credentials?

Question: I just bought a new iPhone SE to replace a destroyed iPhone 5S. It was set up to the point of being able to make calls at the Apple store, but it was not logged into iCloud. At some point after getting home I noticed it was already logged into my router's WiFi. I had not yet manually attempted to log onto my router. I may have logged into iCloud but this device must have a different UDID than my old iPhone 5S. How then was my new iPhone able to automatically log into my router's WiFi?
Answer: iCloud Keychain shares your WiFi networks, including passwords, to all of your devices. So if your new phone had been logged into iCloud, that's where it got the network details.
Comment: Unless your access point is filtering by anything more than correct log/pass, it won't care which device tries to connect to it.
Comment: @Mike Your phone's UDID *isn't* used by apps: Apple haven't accepted apps using UDIDs [for 6 years now](https://www.theverge.com/2013/3/21/4133288/apple-to-finally-stop-accepting-apps-that-use-outdated-udid-device-identifier-may-1st)
Comment: So my understanding about the UDID stated above is incorrect?
Comment: @user1332148 Your phone's UDID is used by apps, and has nothing to do with connecting to WiFi networks. Its MAC address might matter if the network restricts access to whitelisted addresses, but that's not common.
Comment: @grgarside The UDID is no longer used by _third party_ apps. It's still used by Apple apps like iCloud and iTunes.
Answer: In addition to Mike Scott's answer, there is another reason why your WiFi network could have been working when you got home.
When the new phone was set up at the store, if the tech did a backup/restore between phones or otherwise transferred any of your old phone's data over to the new one, then settings would have been transferred as well. In this case, WiFi SSID credentials would typically be part of the transfer process and that would explain why your network was joined when you got home.
Comment: These questions are really not an answer. This is some questions and a guess, but not in any way and answer to the original question.
Comment: @Tyson you're right, I've rephrased the answer to be more "answer-like" than "questioning".


prevent compiling from generating dSYM on OS X (using make)

Question: I've got a c++ project (open source) that does not need to strip debugging symbols by default. With a lot of test executables, there are a lot of dSYM files generated on OS X. I've tried -g3 as a g++ flag to no avail. Ideas?
Thanks!
Juan
Answer: If you're compiling with the "-g" flag, remove it.
Answer: As Ted Mielczarek pointed out, gcc does not produce dSYM files on its own, it simply stores the information needed to produce them in the object files. If you're using make to build your project, it is most likely that there is a separate step in the makefile which runs dsymutil after compiling/linking the executable, see if you can find and remove it.
Answer: Are you compiling via XCode? GCC does not produce .dSYM files, XCode runs dsyumutil to generate them. In my (outdated) XCode 3.2.3, under Project Settings, Build Options -> Debug Information Format, you can choose "DWARF with dSYM File" or just "DWARF". The latter should not result in a dSYM being produced.
However, note that with Apple's toolchain, the DWARF resides in the .o files, and does not get linked into the final binary. (GDB knows how to find it, but it needs the .o files laying around on disk.) If you intend to send the binaries to someone else, you really do need to produce a dSYM to send them along with the binary.


Topology of the power set

Question: Does anyone know a non trivial(that we cannot define on every set) topology defined on the power set of an uncountable set?
Comment: What does "trivial" mean here? The cofinite, cocountable, and particular point topologies (to name just the first three that come to mind) can be defined on any set. Are they trivial?
Comment: I corrected it.By trivial here i mean the topologies that can be defined on any set.
Answer: I think you're asking whether power objects exist in the category of topological spaces. I think the answer is not always: although we have a subobject classifier $\Omega$ (namely the 2-point space with the indiscrete topology), and the exponential object $\Omega^X$ is not guaranteed to exist. The obstruction is the requirement that for every continuous function $f: A \times X \to \Omega$ there must be a unique continuous function $\tilde{f}: A \to \Omega^X$, such that $\tilde{f}(a)(x) = f(a, x)$, and vice-versa. When $X$ is nice enough, e.g. locally compact and Hausdorff, then $\Omega^X$ does exist and has the compact-open topology.
Comment: That's exactly what i wanted to find out!
Answer: You may find this helpful: "A Topology on a Power Set of a Set and Convergence of a Sequence of Sets."
Comment: Current link is [here](http://www1.au.edu.tw/ox_view/edu/tojms/j_paper/Full_text/Vol-21/No-1/21%281%29-2-0333.pdf).  (I would have edited it into the answer but the system won't allow me to change just one character.)
Answer: I don't quite follow your question. But I provide one example anyway. $2^{[0,1]}$ is an example which is compact but not sequentially compact. In fact, we choose a series of points $f_n\in 2^{[0,1]}$ as follows. We definte $f_n(x)$ as the nth digit after writing x in the binary system.
Then, when we choose any subsequence $f_{n_j}$ of $f_n$, we can find a $x\in [0,1]$ such that, after rewriting it in the binary system, it has $n_1$th,$n_2$th, $\cdots$ digits $0,1,0,1,\cdots$, alternatively. Obviously, $f_{n_j}$ has its value in x $0,1,0\cdots$ and thus doesn't have a limit.
But by Tychonoff's theorem, we know this space is compact.
updated: $2^{[0,1]}$ is endowed with product topology.
Comment: I am asking what a topological "open" set would have to be like in the power set
Comment: @t.spero: Xiaochuan is using the product topology on $2^{[0,1]}$. (The reference to Tycohoff's theorem is a clue!) More information is available [on wikipedia](http://en.wikipedia.org/wiki/Product_topology). In concrete terms, if your base set is $S$, open sets on $\mathcal{P}(S)$ are generated by the sets $\mathcal{U}(F, G)$ for finite sets $F$ and $G \in S$, where $\mathcal{U}(F,G)$ is defined to be $\{U \subset S : F \subset U \text{ and } G \cap U = \emptyset\}$. (I believe I have that right, but I am also tired, so no guarantees.)

Topology of the power set


JS window.location.href not showing same value as in address bar

Question: I need to read the url using some JS code in order to extract some parameters and execute some tasks depending on them. However I have two problems:
-The webpage is not mine so I cannot modify anything on it or inspect it in great detail. I just write some script that the client load from its webpage, and executes some functions on load. I can modify this script but not anything else.
-In this functions, I save in a variable the window.location.href value, but when doing some logs in order to verify what is reading, I see that the value does not correspond to the actual url in the address bar. Moreover, if I check the value of window.location.href in the browser console, then the value matches with the address bar!
I check this value at the start of my script and at the end and it does not match in any case. I don't know at which point of the loading does my script start execution, and I don't know what is causing this behaviour.
EDIT: Here is some code, I won't show it all as most of it works fine and doesn't have relation to my problem.
This is what I sent to my client to put in its webpage:
var s1 = document.createElement('script');
s1.src = 'source_of_my_script;
document.head.appendChild(s1);
s1.onload = function () {
    s();
};

This is part of my script:
function s(){
    var my_url_var = window.location.href;
    console.log("1st value", my_url_var);
    var param = extractParamFromUrl(my_url_var); //this functions get some value written in the url

    switch (param){
        case 'value_0':
            // do things
        case 'value_1':
            // do  other things
        defalut:
            // do default actions
    }
    console.log("final value", window.location.href);
}

I cannot show you the exact URLs because of privacy reasons, but they are similar to these ones:
Address bar url (and what i get if I check window.location.href in browser console): https://www.client_dummy_url.com/dummy/cobranded?origin=8000097& ... (more params separated by &)
What I get from window.location.href in script: https://www.client_dummy_url.com/drfd01/main/control.do?action=start&internet=S&app=EP& ... (more params, but not all the ones I want!)
Many thanks!
Comment: Where is this script you can control running, in an iframe?
Comment: Please show us some code.
Answer: After some tries, I managed to get it to work with the solution posted by @Vaibhav at Access parent URL from iframe
//var my_url_var = window.location.href;
var my_url_var = (window.location != window.parent.location)
            ? document.referrer
            : document.location.href;


Column modification date

Question: this is my first day of work, I have zero skills in power apps, so I ask you for help, the task is next. I created a table in share point, it has two columns, I need that when changing in one column, the date of these changes appears in the other in the format dd.mm.yyyy. To solve this problem, I integrated power apps into my share point table, but I don't know how and what code I need to implement. If anyone has the necessary skills and free time, please help me.
Answer: you can do it from diferent way.

SharePoint lists has field to save these information, refer: https://techcommunity.microsoft.com/t5/sharepoint/modified-by-column/m-p/1252278
You can define any format for this field, ex: "dd.mm.yyyy".

Enable list version SharePoint Online, please refer: https://support.microsoft.com/en-us/office/enable-and-configure-versioning-for-a-list-or-library-1555d642-23ee-446a-990a-bcab618c7a37

Regards.
Answer: SharePoint have OOTB columns called [Modified] and [Modified by], one is to record the latest modification time and the other is to record the username corresponding to the modification.
And you can enable the version that you can see the version history.

Column modification date


Which type of In App Purchase should be used for 100s of product with same price?

Question: I have created an app in which I have category of images and every category has unlocked images. There are around 10 categories and each category has 50 locked images. User should be able to pay $0.99 for each image through In App Purchase. Since the price of each image is same so can I use the same product identifier for each image and make that Consumable? Or I will have to add 500 product Identifiers and make them Non Consumable? Please suggest.
Answer: I would create some kind of In-App currency which could be bought with In-App purchases (consumable) and could be used to buy the images. To prevent the user from losing already purchased images I would upload them to iCloud. If the user removes the app from it's device he will still be able to access the image on other device or on the same device after reinstalling the app.
Another advantage of this solution is that you can give away images/IA-currency for free, which wouldn't be possible with the alternative solution. Giving away could be very useful for marketing (for ex. giving away a free image when inviting friends to use the app).
Only weak point is when the user manually deletes the images from iCloud or the user disabled the iCloud feature the images will be lost when the user removes the app. But I ignore that issue and assert that that's the users fault. If you want to workaround that issue you would have to setup a central server and log which user has bought which image.
Comment: By currency means like stars or points? And User will purchase the points and on purchasing the coins the image will be unlocked? Is it?
Comment: Yes, that is what I am meaning.


Gmail is blocking our email, and the IP address listed in the returned email is not our main mail address

Question: Our mx records point to a different IP address than our main public address. However the mail being sent, SMTP is pointing to our main public IP address. The email using the address that SMTP is using is not being accepted by Gmail. I have checked all of our workstations and servers and there is no virus or malware present to indicate that unsolicited spam email is being sent out. How can I change the IP of the SMTP mail to use the same public IP address as the mx record, (mail.domain.com) address? I am assuming that the reason Gmail is blocking our email is because of the IP address being blacklisted. Our mail server IP address is not blacklisted, however. I am going crazy trying to get Gmail to unblock us; they do so for 2 or 3 days and then block us again. I don't know what else I can do.Thank you for your help.
Answer: It would have been helpful if you'd provided details of the MX, and headers from incoming and ouitgoing email.
It sounds like your outgoing email is not routed via the same MTA as the incoming email. This is not an unusual situation, and on its own would rarely be sufficient for a service provider to consider your server as a spam source. Either you are routing your email via a provider who is well known for spamming or you're publishing invalid SPF/RMX data.
Another potential cause is that you are running an open relay/your email server has been compromised and is being used to send UBE (or you are sending UBE yourself).
Comment: I'm sorry. Here is the additional information. the MX record is mail.empressems.com 184.108.40.206. The IP address that is blacklisted is 22.214.171.124 and this is the address on the return header for Gmail is this:  There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.

Comment: @MarieOKeefe This information should be added to your question.
Comment: Too bad...that should be an option. So then I guess I just have one question. like I said Gmail keeps blocking our IP address. Each time this happens, should I just wait for the address to become unblocked or is there something else I can do? I have already filled out their form online. Does filling out this form really expedite the block removal. Thanks so much for your help.
Answer: Exchange always uses the IP with the lowest numeric value to send out emails - in your case that would be the .130 one instead of the .132.
And no, you can't select an IP for Exchange to use. Bizarre!
The only way around seems to be either to remove all lower IP addresses from your network card configuration if you can live with not having the .130 in your server. OR: To use a 3rd party program that is able to route outgoing SMTP traffic via a specific local IP rather than use the default one that Exchange uses.
You can use MultiSendcon (http://www.servolutions.com/multisendcon.htm) for this. MultiSendcon originally is a send connector that can route outgoing emails to different SMTP relay servers but it also can route email directly (dns) without any relays and via specific local IPs. It's originally a product to support different domains going out via different IPs but you can just add one single direct-dns account there with the desired local IP 184.108.40.206 and tag that "*" for all senders.


Vitamin B food source

Question: My question is very simple. What are some good vegetarian food sources for vitamin B? I'm asking this here because I tried to search it on the net but couldn't find much.
Comment: _I tried to search it on the net but couldn't find much_ Really? The search terms "vegetarian" and "vitamin b" on google retrieve more than 3 millions entries. "Shopping question" should really be avoided on Health SE. At least you could provide some links to the research you have already done and explain what is not clear for you. BW
Comment: Actually, this wasn't my point to say you should surf through 3 millions entries. I just wanted to underline the inconsistency of your statement *"I'm asking this here because I tried to search it on the net but couldn't find much"*. As I said, you should at least provide some examples of the links you have found, their contents and what seems "contradictory" to you. Finally, the first hits for the google search retrieves informations from websites such as WebMD and NHS Info for example, which are reliable sources. BW
Comment: @S.Victor They're all contradictory. For instance, I've learnt here that there is vegetarian source for active B12. Google search gives you tens of them. The percentage content is different on every site, sometimes too different. So, I had discredit that research, look for a reliable source. And ofcourse, I can't surf through 3 million search results now, can I?
Comment: @S.Victor alright, I didn't about these sites. Only now I have learnt about their reliability. My bad.
Comment: I'm voting to close this question as off-topic because are off topic unless directly connected to medical treatment.
Answer: Here on Nutrients Review you have lists of foods high in individual vitamins B.
Here on US Department of Agriculture (USDA) are more detailed lists of foods high in individual vitamins and other nutrients.
Roti/chapati, seeds and other plant foods do not contain vitamin B12. As a vegan, you can get vitamin B12 by eating foods that have vitamin B12 added or by taking vitamin B12 supplements. You can get other B vitamins and other nutrients from natural foods.
If a certain food is low in vitamins B or other vitamins, it does not mean it's bad. It's not important how much vitamins a particular food has, but how much vitamins is in your diet (all foods together). You need to get all vitamins regularly, but this does not mean you need to get every single vitamin every single day.
The Vegetarian Resource Group (vrg.org) and VeganHealth.org seem to be reliable sources of nutrition info for vegans.
Answer: The best are deactivated yeast or the extract and
Sunflower seeds(Source USDA) http://nutritiondata.self.com/facts/nut-and-seed-products/3076/2
Other choices(Source USDA) but not limited to; include
Pumpkin seeds
Peanuts
Sesame
Herbs are very good sources of all nutrients; look through these herbs (Source;USDA)
http://www.nutrition-and-you.com/healthy-herbs.html
Answer: Vitamin B is a misnomer, think of it not as 1 vitamin but as "B Vitamins", because there are 8 that are essential to good micro-nutrition.
B vitamins are found in whole unprocessed foods. Processed carbohydrates such as sugar/white flour tend to have lower B vitamin than their unprocessed counterparts. For this reason, it is required by law in many countries (including the United States) that the B vitamins thiamine, riboflavin, niacin, and folic acid be added back to white flour after processing. This is sometimes called "Enriched Flour" on food labels.
Good sources for B vitamins include legumes (pulses or beans), whole grains, potatoes, bananas, chili peppers, tempeh, nutritional yeast, brewer's yeast, and molasses. You can find this information by reading the labels of these products.
So far so good for vegans.
The B12 vitamin is of note because it is not available from plant products, making B12 deficiency a legitimate concern for vegans.
However, manufacturers of plant-based foods will sometimes report B12 content, leading to confusion about what sources yield B12. The confusion arises because the standard US Pharmacopeia (USP) method for measuring the B12 content does not measure the B12 directly. Instead, it measures a bacterial response to the food. Chemical variants of the B12 vitamin found in plant sources are active for bacteria, but cannot be used by the human body. This same phenomenon can cause significant over-reporting of B12 content in other types of foods as well.
Because B-vitamins are water soluble and readily excreted if they are over complimented.
Recommendation for vegetarians/vegans is to supplement Vitamin B12. The rest of the B vitamins should be obtained through legumes (pulses or beans), whole grains, potatoes, bananas and chili peppers.
Comment: Google/Wolfram is your friend, I'm not about to do the analysis for you on your entire diet, consult/pay a nutritionist.
Comment: The flour we use comes from grinding raw wheat from a nearby Grinder. So does it satisfy my needs for B Vitamins - {B12}? And yes, wheat breads(it's called roti I here)  are consumed three times a day.
Comment: If you haven't removed the bran and germ from the wheat before processing it then you can consider it "whole grain". As I said, bread alone will not completely satisfy your needs for B Vitamins. Bread/Roti will only give you B3 and B6.
Comment: What about seeds?
Comment: Haha, they didn't turn out to be very friendly, that'd why I came here. Nevermind. :)

Vitamin B food source


What is the relation between 32bit CRC and the data word size?

Question: if we take 32-bit CRC then the data word size will be 2 to the power of 32(2**32) plus 32 bit for CRC.... or not? Am I missing something?
If I want to write a code in Microsoft Visual C++ for implementing 32-bit CRC then what is the data type I can use? Maybe I am missing the point and talking rubbish.
Basically it is my assignment to implement 32-bit CRC and I am completely at a loss how to go about it.
Sorry if the question is vague. Any help toward implementation, logic, or basic fundamentals will be greatly appreciated.
Answer: CRC-32 is basically the act of dividing two polynomials and returning the remainder.
Recommended introductory reading:

http://en.wikipedia.org/wiki/Cyclic_redundancy_check
http://www.mathpages.com/home/kmath458.htm
http://www.ross.net/crc/download/crc_v3.txt


How does one disable vc-git in emacs?

Question: I'm using emacs over sshfs and a git repository. I enjoy using the git command line and so for this project I do not need vc-git enabled. How do I prevent the loading of vc-git by a .emacs command?
Answer: Remove git from the list of backends handled by vc-mode:
(delete 'Git vc-handled-backends)

or remove all source control hooks:
(setq vc-handled-backends ())

Comment: +1 (setq vc-handled-backends ()) worked just fine. Not only Emacs starts faster now, but file opening is much quicker too, thanks!
Comment: This variable can also be modified or cleared using `customize`.
Comment: The solution with delete is incorrect because delete does not modify the argument, just returns the modified list. Use this instead:
(setq vc-handled-backends (delete 'Git vc-handled-backends))
Comment: Here in 2023, I suddenly experienced unacceptable waiting times when opening files under a git clone folder with Emacs/Cygwin. Adding `(delete 'Git vc-handled-backends)` to `.emacs` solved the problem. `(setq vc-handled-backends (delete 'Git vc-handled-backends))` also worked, but I saw no difference between the two.
Answer: Remove it from find-file-hook. This should disable the backend:
(remove-hook 'find-file-hook 'vc-find-file-hook)

you might need a (require 'vc) before the above line to get the timing right.  Or perhaps wrap it like so:
(eval-after-load "vc" '(remove-hook 'find-file-hook 'vc-find-file-hook))

to get the timing right.
Comment: I also had `'vc-refresh-state` in the hook so I've removed it as well `(remove-hook 'find-file-hook 'vc-refresh-state)`
Answer: Or you can disable the entire version control thing in emacs
;;disable the version control

(setq vc-handled-backends nil)

worked for me.
Answer: I'd also really recommend magit (a different emacs git mode.) I, too, prefer command line for everything but this one's really well done and allows you to code more and "git" less. Particularly staging and unstaging code / seeing a diff of your changes before sending them out, viewing stashes, and pulling / pushing while staying inside of emacs is great.
Answer: This also works:
(setq vc-ignore-dir-regexp ".+")

or
(setq vc-ignore-dir-regexp "")

as sugested by @Stefan in comment
this will speed up reading as well as saving files. and you can provide the regex you want so you can make git work for some directories and don't for others.
Comment: @Stefan yes it should be `".+"` I though that . need to be escaped, it was working because it matched .git directory.
Comment: `".+"` would mean "ignore any dir whose name has at least one non-LF char in it".  IOW, it ignores all dirs except the directories called `""`, `"\n"`, `"\n\n"`, ... I think it's a rather odd choice: `""` is shorter and means "ignore *all* dirs", which sounds closer to what you're suggesting.

How does one disable vc-git in emacs?


Connect local network machine as a FTP machine

Question: I have network of 20-30 machine.
I want to connect to other machines from my machine as FTP.
Is that possible?
Answer: What exactly are you trying to accomplish? Why do you want to connect via FTP?
Generally, you can connect with an FTP-client to every machine that has an FTP Server running and correctly configured.
Answer: You can deploy and configure a FTP server and enter those local machines' resources' paths to that FTP server. Then you simply connect to that FTP server and browse paths which will be the resources of those local machines actually...


If the first D note (in the 1st beam) is flat, does that mean the next D note (in the 2nd beam) is also flat? (see photo)

Question: If the first D note (in the 1st beam) is flat, does that mean the next D note (in the 2nd beam) is also flat? (see photo)
Answer: Yes, it is flat because it's in the same bar, and the same octave.
A D on a different octave, on the other hand, would not be flattened by that initial flat.
Answer: An accidental in any bar will always and only affect the pitch concerned. So, here, any other D note in that bar only at that same pitch will be affected by the accidental (here, a flat sign). The very next barline will cancel any accidentals that occurred in the previous bar.