What makes the canonical link function special in GLMs?
What is the difference between a "link function" and a "canonical link function" for GLM
How can I use Photoshop to imitate a photo taken with a low-quality camera? How can I create an image in Photoshop that imitates a photo taken with a low-quality phone camera? Examples of qualities I want to simulate:   blurring in some areas caused by a dirty lens low quality exposure handling in the darkroom noise   Some examples: Should I upgrade to the "mainline" kernels? Newer "mainline" versions of the kernel are available from the , e.g. 3.4 and 3.5, while Ubuntu 12.04 is on 3.2.   What are the mainline kernels? Are they better than my existing kernel? What are the pros and cons of upgrading to a mainline kernel? Will I easily be able to go back? Gambler's ruin and coin toss I'm trying to show that $R = \mathbb{Q}[X,Y]/(Y^2-X^3)$ is not a UFD, but I got stuck.  To prove this, I could try to find two "different" factorisations for one element, but I am not familiar with this, so I tried to use a lemma and one of the previous exercises. If my syllabus is right, in every UFD counts $$ x \ \text{is irreducible} \quad \iff \quad x \ \text{is prime}$$ My syllabus also states that the elements $\bar{X}, \bar{Y} \in R$ are irreducible. So I tried to show that at least one of the elements $\bar{X}, \bar{Y} \in R$ does not generate a prime ideal.  This would mean that I should find two polynomials $f,g \in \mathbb{Q}[X,Y]$, such that  $$\exists p \in \mathbb{Q}[X,Y], \quad fg - pX \in (Y^2-X^3)$$ and $$\forall q \in \mathbb{Q}[X,Y], \quad f-qX \notin (Y^2-X^3) \ \wedge \ g-qX \notin(Y^2-X^3)$$ or the same thing but then for $Y$.  I hope that you can tell me if this approach is correct, and provide me a hint. I'd appreciate it if you told me the solution, but please start your answer with a hint, clearly separated from the rest. I have heard that .NET is not free and that I have to pay Microsoft if I develop a .NET application.  Is this true?  If so:   What do I have to pay? I'm a subscriber to the MSDN via the Academic Alliance (we download a variety of Microsoft Software products for free, like VS2008 and Windows Server 2008). Do I have to pay for the software that I make with these tools? What about web apps with ASP.NET? Is there a payment due when I host my application or do I just pay for the technology?   EDIT:  So what you are saying is that it's the same to develop a web application using ASP.NET or PHP (ignoring technical issues, just payment side), all what I have to pay is the hosting fees?  EDIT 2:  .NET rules :) The -k option (or --convert-link) will convert links in your web pages to relative after the download finishes, such as the man page says:     After the download is complete,   convert the links in the document to   make them suitable for local viewing.   This affects not only the visible   hyperlinks, but any part of the   document that links to external   content, such as embedded images,   links to style sheets, hyperlinks to   non-HTML content, etc.   So, if I didn't specify -k, can I run wget again after the download and fix that, and if so, what would be the proper command? My guess is wget -c [previous options used] [url] and run it in the same working directory as the file were downloaded to. I would like to associate the last installed version of my Mac OS X application with a certain type of file. A little experimentation shows that the info.plist file seems to be read and interpreted by the operating system when launching the application, not when dragging the application bundle to the disk.  does not say much on that topic.  Is there any way, using a simple .dmg image as installation medium, to make sure the system associates that particular file type with my newly installed app without having to launch it first?  I should clarify that I want this to be done automatically during the installation (I don't want my users to have to do it themselves). What exactly is an environment variable? I know that VARIABLE=value creates an environment variable, and export VARIABLE=value makes it available to processes created by the current shell. env shows the current environment variables, but where do they live? What comprises an environment variable (or an environment, for that matter)? Select first occurring element after another element How to use ssh to transfer files from computer a to local computer I am trying to get some files off of my school Linux account using ssh. I have got the connection to work using:  scp &lt;school_server&gt;: ~/folder I want ~/where I want to go.    But when it goes to transfer folder it gives me the message:  not a regular file    The file contains .java files, and I want the whole folder. Headers of \chapters* take the headers of their previous \chapter When using book.cls and using \chapter* after a \chapter, the header used in \chapter* is wrong. An example is pasted below.   Is there any known workaround for that? I have tried quite some tricks without success.   \documentclass[]{book}  \begin{document}  \chapter{First Chapter} aslkjdf  \chapter*{Unnumbered Chapter} The GNU General Public License is a free, copyleft license for software and other kinds of works.  The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.  When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.  To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.  For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.  Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.  For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions.  Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.  Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.  The precise terms and conditions for copying, distribution and modification follow.  \end{document} How can I fix a 404 Error when using a PPA or updating my package lists? PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors? Is there a way to resolve probability of an event, given another event that never happens? Mathematically speaking the problem is:  Given that $P(B) = 0$,  $$P(A|B)=\frac{P(A \cap B)}{P(B)} = \frac{0}{0}$$  Is this probability vacuously $0$ of $1$? Can we show that it's one or the other? Stack Overflow duplicated layer bug Grant Select on all Tables Owned By Specific User What's the best way to invite a user to answer a question on Stack Overflow? On several occasions, I was reading a question thinking "I know a guy that knows the answer to this" and that guy (or gal) also happens to be a registered user. How can I bring this to the attention of this user? What are "Commited Memory", "Cached", "Paged", "Not-paged pool" & How They are Different with "In-Use Memory" Cardinality of the set of all (real) discontinuous functions This is a question from the book Introduction to Set Theory (Hrbacek and Jech), chapter 5, question 2.6.     (Show that) The cardinality of the set of all discontinuous functions is $2^{2^{\aleph_0}}$. [Hint: Using exercise 2.5, show that $|\mathbb{R}^\mathbb{R}-C|=2^{2^{\aleph_0}}$ whenever $|C|\leq 2^{\aleph_0}$.]   Exercise 2.5, as referred to in the hint, provides the following result:     For $n&gt;0$, $n \cdot 2^{2^{\aleph_0}} = \aleph_0 \cdot 2^{2^{\aleph_0}} = 2^{\aleph_0} \cdot 2^{2^{\aleph_0}} = 2^{2^{\aleph_0}} \cdot 2^{2^{\aleph_0}} = (2^{2^{\aleph_0}})^n = (2^{2^{\aleph_0}})^{\aleph_0} = (2^{2^{\aleph_0}})^{2^{\aleph_0}}=2^{2^{\aleph_0}}$.   The only way I could answer this question was by making use of two theorems stated later  in the same textbook. First, it is easy to prove that $|\mathbb{R}^\mathbb{R}-C|$ is an infinite set, since if it was finite we would have \begin{equation}2^{2^{\aleph_0}}=|\mathbb{R}^\mathbb{R}|=|\mathbb{R}^\mathbb{R}-C|+|C| \leq n+2^{\aleph_0}=2^{\aleph_0}&lt; 2^{2^{\aleph_0}},\end{equation}which is a contradiction. Now I make use of a theorem requiring the axiom of choice: For every infinite set $S$ there exists a unique aleph $\aleph_\alpha$ such that $|S|=\aleph_\alpha$. So I let $|\mathbb{R}^\mathbb{R}-C|=\aleph_\alpha$ for some ordinal $\alpha$. Now assume $\aleph_\alpha &lt; 2^{2^{\aleph_0}}$. Here I make use of another theorem, which i am not sure I am allowed to do: For every $\alpha$ and $\beta$ such that $\alpha \leq \beta$, we have $\aleph_\alpha+\aleph_\beta=\aleph_\beta$. So I basically then say either $|\mathbb{R}^\mathbb{R}-C|+|C|=\aleph_\alpha$ or $|\mathbb{R}^\mathbb{R}-C|+|C|=2^{\aleph_0}$, depending on whether $\aleph_\alpha \leq 2^{\aleph_0}$ or vice-versa. The assumption I am making is that $2^{\aleph_0}=\aleph_1$, which as I understand it is basically equivalent to the continuum hypothesis, as we are saying that the least uncountable number is $\aleph_1$ (but by the previous theorem requiring the axiom of choice this seems reasonable?). So anyway assuming I can do that, we again have a contradiction since then we are saying $|\mathbb{R}^\mathbb{R}|=2^{\aleph_0}&lt;2^{2^{\aleph_0}}$ or $|\mathbb{R}^\mathbb{R}|=\aleph_\alpha &lt; 2^{2^{\aleph_0}}$.  My main problem with my proof is that I am not making use of the result given in exercise 2.5 as suggested in the hint. Can anyone help with a proof making use of this result (stated in the second block quote above). In Leibniz notation, the 2nd derivative is written as $$\dfrac{\mathrm d^2y}{\mathrm dx^2}\ ?$$  Why is the location of the $2$ in different places in the $\mathrm dy/\mathrm dx$ terms? Same update keeps showing up everyday