downloading an app from terminal
Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?
Negative pressure Where's the Strangedupe blog post? Previously, in order to explain the benefits of (certain limited kinds of) duplication on Stack Exchange sites, I've seen a blog.stackoverflow blogpost with the words "Dr. Strangedupe" in the title.  The post comes up in a search on the new blog, but       Can we please bring this post back? I'd love to link to it when , to reassure the questioner that there is value in not deleting their question because of search terms, but the blog post explained it a lot better than I could in a comment. What does the human body use oxygen for besides the final electron acceptor in the electron transport chain? My biology teachers never explained why animals need to breathe oxygen, just that we organisms die if we don't get oxygen for too long. Maybe one of them happened to mention that its used to make ATP. Now in my AP Biology class we finally learned the specifics of how oxygen is used in the  due to its high electronegativity. But I assume this probably isn't the only reason we need oxygen.   What other purposes does the oxygen we take in through respiration serve? Does oxygen deprivation result in death just due to the halting of ATP production, or is there some other reason as well? What percentage of the oxygen we take in through respiration is expelled later through the breath as carbon dioxide? What is a good word to describe someone who is empathetic, quick, and witty in conversation What's the preferred method of writing AJAX-enabled plugins? PostgreSQL multi-column unique constraint and NULL values I have a table like the following:  create table my_table (     id   int8 not null,     id_A int8 not null,     id_B int8 not null,     id_C int8 null,     constraint pk_my_table primary key (id),     constraint u_constrainte unique (id_A, id_B, id_C) );   And I want (id_A, id_B, id_C) to be distinct in any situation. So the following two inserts must result in an error:  INSERT INTO my_table VALUES (1, 1, 2, NULL); INSERT INTO my_table VALUES (2, 1, 2, NULL);   But it doesn't behave as expected because according to the documentation, two NULL values are not compared to each other, so both inserts pass without error.  How can I guarantee my unique constraint even if id_C can be NULL in this case? Actually, the real question is: can I guarantee this kind of uniqueness in "pure sql" or do I have to implement it on a higher level (java in my case)? Prove a graph Containing $2k$ odd vertices contains $k$ distinct trails I'm reading the book Graphs and Their Uses which contains the following theorem and proof:     THEOREM 2.3. A connected graph with 2k odd vertices contains a family   of k distinct trails which, together, traverse all edges of the graph   exactly once.       PROOF. Let the odd vertices in the graph be denoted by   in some order.       $a_1,a_2,\dots,a_k$ and $b_1,b_2,\dots,b_k$      When we add the $k$ edges $a_lb_l, a_2b_2 ,\dots, a_kb_k$ to the graph, all   vertices become even and there is an Eulerian trail T. When these   edges are dropped out again, T falls into k separate trails covering   the edges in the original graph.   However this doesn't seem to make sense since in the graph whose vertices have degrees 3, 1, 1, 1 there is no way to add 2 edges in such a way that the degree of all odd vertices becomes even.  What am I missing here? What is the best format to capture addresses for a universal user-base? What is the best and most usable format to capture address information from a universal user base? I was thinking to have the system detect the country by IP address and have that selected by default, and then state/province droplist would be populated accordingly. But the issue is some countries have states and provinces and some do not. Some have postal codes and some do not. Is there a universal standard to capture complete address info to ensure efficiency for most users?  FYI: I did research on here and while there are some questions that are close, none are about this exact same question (unless I missed something) Suppose $f$ is a continuous, strictly increasing function defined on a closed interval $[a,b]$ such that $f^{-1}$ is the inverse function of $f$. Prove that,   $$\int_{a}^bf(x)dx+\int_{f(a)}^{f(b)}f^{-1}(x)dx=bf(b)-af(a)$$   A high school student or a Calculus first year student will simply, possibly, apply change of variable technique, then integration by parts and he/she will arrive at the answer without giving much thought into the process. A smarter student would probably compare the integrals with areas and conclude that the equality is immediate.  However, I am an undergrad student of Analysis and I would want to solve the problem "carefully". That is, I wouldn't want to forget my definitions, and the conditions of each technique. For example, while applying change of variables technique, I cannot apply it blindly; I must be prudent enough to realize that the criterion to apply it includes continuous differentiability of a function. Simply with $f$ continuous, I cannot apply change of variables technique.  Is there any method to solve this problem rigorously? One may apply the techniques of integration (by parts, change of variables, etc.) only after proper justification.  The reason I am not adding any work of mine is simply that I could not proceed even one line since I am not given $f$ is differentiable. However, this seems to hold for non-differentiable functions also.  I would really want some help. Pictorial proofs and/or area arguments are invalid. Can I prepay a Credit Card to make a Large Purchase greater than my credit limit? I want to make a large purchase at a retail store to the sum of $10,000 but the credit limit on my card is set at $2000.  If I send $10K to my credit card will the purchase be allowed to go through?  Not sure if the credit limit is a hard limit or not?  I don't want to be left embarrassed if my card is declined in the store lol.  I called my bank but the answer they gave wasn't too convincing. It was kind of "Errr yes i think its OK!"  Does any one know first hand? Showing the sequence converges to the square root For any $a &gt; 0$, I have to show the sequence $x_{n+1}$ $=$  $ \frac 12$($x_n+ $ $ \frac {a} {x_n}$)  converges to the square root of $a$ for any $x_1&gt;0$.  If I assume the limit exists ( denoted by $x$) then,  $x$ $=$  $ \frac 12$($x+ $ $ \frac {a} {x}$) can be solved to $x^2 = a$  How could I show that it does exist? Is there any way to get the windows cmd shell to expand wildcard paths? Occasionally, the cmd shell's inability to expand wildcard paths can really be an inconvenience. I had to pass 100 files in a directory to a program, and couldn't type *.ext. Instead, I used mingw's 'ls' to dump the list to a file, then replaced newlines with spaces, copied and pasted into cmd. Quite a nightmare.  I suspect the answer will be no, but has anyone dealt with this or come up with any way to make this easier? Can we simply rename an app if they are different versions and keep them both? For example, I have Xcode 4.4.1, and now Xcode 4.5 Golden Master (GM) version is available, but it is also called Xcode (when the .dmg is mounted as an disc image, it shows only one app (or folder), called Xcode)  I think the way is just to double click on the .dmg file, and then drag and drop that app into our Applications folder.  But since the current Xcode and Xcode 4.5GM have the same name, can the new one just be renamed and so we can have both versions on our machine?  I was worried that what if the app writes back data to the /Applications/Xcode folder, then the GM version can write unexpected data for the 4.4.1 version.  And will it work with other software, such as Xcode 3.2, Xcode 3.3, or even different versions of Microsoft Office and Adobe Photoshop? Is it legal to add your publications to ResearchGate? I recently created a profile on . And to add your publications list it requires you to upload the paper. Is it legal to upload published journal articles on public servers, where everyone can download it for free? For a presentation with Beamer, I would like to have a slide where a long list of formulas (maybe mixed with text) scrolls automatically within a certain part of the slide. This should look like e.g. closing credits in movies.   I have tried the idea from  based on animateinline from the , but whenever I use environments like \begin{equation} ... \end{equation} or commands like \textcolor{red}{...} I get an error:  TeX capacity exceeded, sorry [main memory size=3000000]. \end{frame}   Ideally, the formulas/the text should be given within the document itself, but if a solution with an external PDF works fine, I'll take it!  Any ideas how that might work? I'm using R(3.1.1), and ARIMA models for forecasting. I would like to know what should be the &quot;frequency&quot; parameter, which is assigned in the ts() function, if im using time series data which is:  separated by minutes and is spread over 180 days (1440 minutes/day) separated by seconds and is spread over 180 days (86,400 seconds/day).  If I recall right the definition, a &quot;frequency&quot; in ts in R, is the number of observations per &quot;season&quot;. Question part 1: What is the &quot;season&quot; in my case? If the season is &quot;day&quot;, then is the &quot;frequency&quot; for minutes = 1440 and 86,400 for seconds? Question part 2: Could the &quot;frequency&quot;  also depend on what I am trying to achieve/forecast? for example, in my case, I'd like to have a very short-term forecast. One-step ahead of 10minutes each time. Would it then be possible to consider the season as an hour instead of a day? In that case frequency= 60 for minutes, frequency = 3600 for seconds? I've tried for example to use frequency = 60 for the minute data and got better results compared to frequency = 1440 (used fourier see link below by Hyndman)  (The comparison was made by using MAPE for the measure of forecast accuracy) In case the results are complete arbitrary, and the frequency cannot be changed. What would be actually the interpretation of using freq = 60 on my data? I also think it's worth mentioning that my data contains seasonality at every hour and every two hours (by observing the raw data and the Autocorrelation function) Hi I was looking to install this with or under VMware on windows 7 64bit, is this possiable and where can I find instructions on how to do so? I have searched the site and can not find anything for help on installing this with VMware.  Also I have VMware Workstation do I need VMware player? Why use hex? Hey! I was looking at this code at   I noticed that in some situations they used hex numbers, like in line 134:  for (j = 1; val &amp;&amp; j &lt;= 0x80; j &lt;&lt;= 1, q++)   Now why would they use the 0x80? I am not that good with hex but I found an online hex to decimal and it gave me 128 for 0x80.  Also before line 134, on line 114 they have this:  small_n = (n &amp; 0xffff0000) == 0;   The hex to decimal gave me 4294901760 for that hex number. So here in this line they are making a bit AND and comparing the result to 0??  Why not just use the number? Can anyone please explain and please do give examples of other situations.  Also I have seen large lines of code where it's just hex numbers and never really understood why :( I'm playing around with fdisk and I tried to create a partition on an empty USB drive. Here's how that went: Command (m for help): n Partition number (1-128, default 1): 1 First sector (34-61187102, default 2048): 2048 Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-61187102, default 61187102): +30000000           Created a new partition 1 of type 'Linux filesystem' and of size 14,3 GiB.  so just one partition with 30 million sectors. However, when I check how many sectors it contains I get:  I'm checking with a different program and I see again that additional sector:  Sorry for the pettiness :) I'm learning. Compiler Errors in atlwin.h