How can I vote on 600 questions but only 25% of them are on questions?  Did it originally mean "600 posts"?
There is a badge named Electorate which is going to be awarded on "Voted on 600 questions and 25% or more of total votes are on questions". Can somebody explain this to me?  Voted on 600 Question and 25% are on Question? is this  means   Voted on 600 Posts and 25% are on Question  Can't SO place some easy text or Definitions for average users?
I have multiple datasets that I am attempting to use principal component analysis (PCA) on in order to infer the underlying structure of the data.  I'm attempting to predict growth increment of conifers (the response which apparently needed to be cube root transformed for my original linear models).  My predictor variables include: continuous (some log-transformed like size-related variables, some compositional, and some traditionally scaled); binary; ordinal; and nominal (of which I'm pretty sure I can order with respect to site productivity).  I'm mostly attempting to make inferences because some of my previous models from linear regression have not produced significant terms corresponding to categories like health or climate and I feel that they should have.  I've read in Joliffe (2002) that I might want to leave my compositional data uncentered.  Forgive my naiveté, but I'm wondering if I should also do this for my binary data.  It also seems that I might not want to scale these since they're already on a 0 - 1 scale but I'm not sure.  After only using my continuous predictors (including compositional variables), it appears that a size principal component makes up the largest portion of the variability and Joliffe also mentions that one might want to attempt a "double-centering" of the log-transformed data if this is the case.  I don't know if this is even possible since the log-transformed data only makes up a small portion of my datasets.  Finally, I should ask if having such a combination of data types will complicate analysis so much that it will make inferences unreliable.  I am currently using R for this analysis.  Thank you. I have the following $n\times n$ matrix:  $$A=\begin{bmatrix} a &amp; b &amp; \ldots &amp; b\\ b &amp; a &amp; \ldots &amp; b\\ \vdots &amp; \vdots &amp; \ddots &amp; \vdots\\ b &amp; b &amp; \ldots &amp; a\end{bmatrix}$$  where $0 &lt; b &lt; a$.  I am interested in the expression for the determinant $\det[A]$ in terms of $a$, $b$ and $n$.  This seems like a trivial problem, as the matrix $A$ has such a nice structure, but my linear algebra skills are pretty rusty and I can't figure it out.  Any help would be appreciated. I write about  that shows a big probability mass. It's a web-based interactive visualization of topics estimated using Latent Dirichlet Allocation that is built using a combination of R and D3; the default for scaling the set of inter-topic distances defaults to Principal Components, but other algorithms are also enabled.    This is the way that it finally shows with some data I found online and used to understand Latent Dirichlet Allocation topic modeling. As far as I understand, this graph is ideal to give out final names to each topic according to the frequency or relevance of each term given the topic but I've got two questions:   1. What would you simply say about topic 8 position on the graph? Meaning that I can't tell what each square represents in this graph, I can't tell in plain words what's the difference between topic 1 and 10, or topic 8 and 3, given their position on this graph?   2. What can you say about the big gray line in comparison with the red filling when lambda is 0? I think I get that when lambda is 1, it's meaning about plain frequency of the term in the whole corpus vs the frequency of the terms in that topic, but I'm not sure I get it with putting more weight in the ratio from red to gray: what is the gray line saying about that term and how is red contrasting?  You can get this for a model named lda_model$plot() found .   I am looking for the main idea at least. If there is info I need to add please tell me. For any matrix $A$, $AA^T$ is symmetric, and thereby diagonalizable (Spectral Theorem). This implies that $AA^T$ has n linearly independent eigenvectors and therefore full rank.  Does this imply that for any matrix $A$, $AA^T$ is always invertible ? I know there is something wrong here because from the above chain we can conclude that a symmetric matrix is always invertible, which is definitely not true.  Could someone please point out where I am going wrong? Is there a max length for an array in C++?  Is it a C++ limit or does it depend on my machine? Is it tweakable? Does it depend on the type the array is made of?  Can I break that limit somehow or do I have to search for a better way of storing information? And what should be the simplest way?  What I have to do is storing long long int on an array, I'm working in a Linux environment. My question is: what do I have to do if I need to store an array of N long long integers with N > 10 digits?  I need this because I'm writing some cryptographic algorithm (as for example the p-Pollard) for school, and hit this wall of integers and length of arrays representation. What are the odd of a single coin toss after many consecutive ones? I have little knowledge of probability and have recently been thinking of a math problem I am sure you guys could answer  If for example I tossed a coin ten times and got all heads, would the odds of the next coin toss beeing heads be 50 50 or s very low as the odds of getting 11 in a row is tiny?   Thanks I file 83(b) election, but did't include a copy of it in that year’s tax return Making a log4j console appender use different colors for different threads Should we have a tag for significant points in time? There are many discussions about the current incidence. For example:          Should we have a whole tag for this incidence? In general, if in the future there are more crises and incidences like this, should they have their own tags too? I feel it's fine, as we have specific tags for individual events like . And, should we have a  tag?    Related:        Note that these questions are specifically about the conflict 2019, while this question is simply about creating meta tags for significant events. Calling C/C++ from Python? View vote count button on mobile On the mobile site, can there be a button directly below the vote up/down buttons for viewing vote counts? When I am using the mobile site and I want to view vote counts, I have to switch to the full site to do it which is very inconvenient.   It could be a small link that says "vote counts," because I don't know what the button would be (the letter "V?" a "+/-" thing? I have no idea).  Related:  , but I am requesting an additional button below the vote buttons. That way you won't accidentally click a vote button. I am trying to split a selected polygon ("regions") with a selected line from another layer ("streets") in QGIS 3.8.3. In the example below, I want to split the selected polygon coloured in yellow with the street pointed at by the blue arrow.    After reading the post , I realized I can't find it either. I installed the plugin, but the tool seems to be missing from my toolbar: Big Endian vs. Little Endian in Qiskit I've noticed that Q# favors Little Endian. Meaning that most operations are designed for this type of encoding.  Is is it the same with Qiskit? Post hoc test after ANOVA with repeated measures using R What is the meaning of the axes in t-SNE? I'm currently trying to wrap my head around the  math. Unfortunately, there is still one question I can't answer satisfactorily: What is the actual meaning of the axes in a t-SNE graph? If I were to give a presentation on this topic or include it in any publication: How would I label the axes appropriately?  P.S: I read  Reddit question but the answers given there (such as "it depends on interpretation and domain knowledge"), don't really help me to understand this. I would like to add a new cable outlet to an outside wall and wanted to find out what kind of drill bit is needed to drill through and feed the coax cable as well as anything else to be mindful of. Comcast wanted $70 for a new outlet installation ($30 install, $40 tech visit), so I figured I could do it myself. The part that I'm most unfamiliar with is how to properly weather seal it. The outside just has vinyl siding and there's no electrical outlets nearby.  So far, I think I need the following   Coax Cable Coax Cable Wall Plate Long drill bit Add a 3-way Cable Splitter to cable box Weather sealer? newenvironment: error with \begin{align} and \end{align} In the example below, an error is caused by \begin{align} and \end{align} but I do not see why:  \documentclass{book} \usepackage{amsmath} \newenvironment{subalign}{\begin{subequations}\begin{align}}{\end{align}\end{subequations}} \begin{document} \begin{subalign}      a&amp;=b\\     &amp;=b \end{subalign} \end{document} Why does no line appear when using Interpolate Line in ArcMap? How do I redirect a domain to another domain locally? My /etc/hosts file looks like this:  127.0.0.1       localhost 10.20.7.67      testsitealpha.dev othersite.dev   testsitebeta.dev   The first two work. The last one doesn't. Why not? How do I make it work? The reason I am doing this, is because I have a test server (othersite.com), which is on the local network, but it's ip can vary. e.g. 10.20.7.98 one day, 10.20.7.35 another, etc.  So, how do I make my system always resolve testsitebeta.dev to the same ip as othersite.dev? Do I need a Turkey transit visa for a layover?