C code binding with a Qt gui
Does Qt have a C interface?
Editing the "Self-Learner" Badge Description Stemming from  the text for "Self-Learner" badge is pretty easy to get confused by.  Current Text     Answered your own question with score of 3 or more    Issue  The person in the above question was confused as they thought they needed to answer their own question, and that the question had to have a score of 3 or more. What it actually means is that they have to answer their own question, and the answer needs to have a score of three or more. The way it is phrased is ambiguous, so why not make it clear?  Suggestion  Edit the text as follows:     Provide an answer with a score of 3 or more to your own question   No more confusion. What are the units of entropy of a normal distribution? I have a random process that follows a normal distribution. It's parameters are mean = 35 units, std.dev. = 8 units. I've seen from the  for the normal distribution that there is a formula to calculate the entropy. So plugging in the figures as:- $$     .5\log\left(2\pi e^1 8\cdot 8\right) $$ I get a value of 1.52, which I take to be  per sample.  My question is what are these units?  What thing do I have 1.52 of?    is (typically) measured in units of bits, after Claude Shannon's definition.  So can I take it that each sample generates 1.52 bits of entropy?  Clearly recording those samples generates information and therefore occupies a real and discrete amount of storage space. Ergo entropy cannot be unit less. How can I effectively use the Coppersmith? I've been playing Dominion with the base + Intrigue sets for a while now, and one of the cards that I have trouble wrapping my mind around is the Coppersmith.  In theory, it seems like a great card - it allows you to make all of your Coppers into Silvers, and in some cases - even Gold. However, I have yet to build a deck during a game that manages to use it effectively. Usually, in order to pull one or two of those with a nice amount of coppers, I need to create a deck that relies heavily on +cards/+actions chains, and the Coppersmith only begins to affect the game too late for it to be of any use.  So... how can this card be effectively used? Question: Suppose that $R$ is a commutative ring without zero-divisors.   Show that the characteristic of $R$ is either $0$ or prime.   I have established that every element in a commutative ring $R$ without zero divisors have the same additive order $n$.   Now, if no such additive order n exists, then the characteristic of $R$ is $0$.  Obviously, if a finite additive order exists, Char of $R$ is finite.  How do I show that Char of $R$ is prime? It probably involves lagrange's theorem and the order of the element in $R$.  Hint is appreciated.  Thanks in advance. This is exercise 1.6.1 of   Suppose that 501 distinct integers are selected from 1 . . . 1000. Show that there are distinct selected integers $a$ and $b$ such that $a | b$. Show that this is not always true if 500 integers are selected.  This seems like it should be simple but it's has been stumping me for a few days.  Here's my idea for a proof:  Let $S$ be a set of 500 distinct integers between 1 and 1000 that don't divide each other. Let $S_{1-500}$ and $S_{501-1000}$ partition $S$ into sets containing the elements ≤ and > than 500, respectively. Then consider $2 S_{1-500}$ and $\frac{1}{2}S_{501-1000}$, the result of multiplying the elements of these sets by 2 and 1/2, respectively. Because elements of S are coprime, $S_{1-500}$, $S_{501-1000}$, $2 S_{1-500}$, and $\frac{1}{2}S_{501-1000}$, are disjoint. Also note that each of these sets is a subset of the integers from 1 to 1000. One can deduce that the cardinality of the union of these sets is 1000, and therefore they form a partition of the integers from 1 to 1000.  Now, I know this demonstrates that you can't add another number to $S$ that is coprime with all the elements in $S$, which means that a coprime subset of the integers from 1 to 1000 can have at most 500 elements. Can someone articulate why this is true for me? Also, this was in a section on the Pigeonhole principle, can someone rework the proof to utilize that, and possibly make it simpler? Thanks. QM without complex numbers When I try to move, rename, or delete a file named ␀in Finder, I get this error message:     The operation can't be completed, because an unexpected error occured (error code -50).   With mv, rm or find -delete in Terminal   rm: /Library/␀: Invalid argument  mv: rename /Library/␀ to /tmp/␀: Invalid argument  find: -delete: unlink(/Library/␀): Invalid argument   Can I move or delete this file in Mac OS X or do I have to use another operating system?  I even tried creating a file with this name in /tmp and it has not gone away since 8 reboots. What is the meaning of "this" in Java? The extension of smooth function If $U$ is a bounded domain in $\mathbb R^n$ whose boundary is smooth, and $f$ is a smooth function on $U$ whose partial derivatives of all orders have a continuous extensions to $\bar U$. For an arbitrary domain $V \supseteq \bar U$, is there a smooth function $\tilde f$ on $V$ extending $f$? Converse to Hilbert basis theorem Prove the converse to Hilbert basis theoren:     If the polynomial ring $R[x]$ is Noetherian, then $R$ is noetherian. How did Rita know she lost the power? In Edge of Tomorrow, Emily Blunt's character, Rita Vrataski, had the time-resetting power previously.  She details the backstory of how she gained it, and how she lost it.  However, how did she know when she lost the power?  It's only triggered when the wielder dies.  Obviously she didn't die after losing the power, so how did she know the power was gone? Combining all the address fields into one? Alternatives to "and/or"? How do I change the default file manager back to Nautilus? I am learning Linux and I was trying the gzip command. I tried it on a folder which has a hierarchy like  Personal/Folder1/file1.amr Personal/Folder2/file2.amr Personal/Folder3/file3.amr Personal/Folder4/file4.amr   I ran     "gzip -r Personal" and now its like  Personal/Folder1/file1.amr.gz Personal/Folder2/file2.amr.gz Personal/Folder3/file3.amr.gz Personal/Folder4/file4.amr.gz   How do I go back? Is an idle temperature of 66°C for the A10-6800K CPU normal? I have an A10-6800K CPU and Piriform Speccy says that my CPU temp is 66 celcius in idle, the same goes for HWMonitor.  Is this normal/ideal? I have a  with a . Prove $\operatorname{rank}A^TA=\operatorname{rank}A$ for any $A\in M_{m \times n}$ How can I prove $\operatorname{rank}A^TA=\operatorname{rank}A$ for any $A\in M_{m \times n}$?   This is an exercise in my textbook associated with orthogonal projections and Gram-Schmidt process, but I am unsure how they are relevant. Complex zeros of the polynomials $\sum_{k=0}^{n} z^k/k!$, inside balls Java Generics: List, List, List How can I provide anonymous user to access my REST GET API without providing any auth information? The Drupal 8 REST UI configuration page asks me to select Authentication providers for GET method; otherwise, it doesn't allow me to export the REST request.  How can I provide anonymous user to access my REST GET API without providing any auth information?