avoid overplotting tons of points in R using ggplot2
Scatterplot with too many points
Opening a context menu (with the Menu key) Cat 5/6 in same conduit as power: is NM-B required, or is THHN acceptable? How do I get the Glare node to output transparent instead of Black background This is what I have so far:  The rendered image has a transparent background, but the glare filter creates an output with a black background, so after merging the two togheter, the background turns black but I need it to be transparent, what can I do? removeGroup() in QGIS 3 I am updating a plugin from QGIS 2 to 3.  I need to iterate through the groups (the names are dynamic) and remove them with their respective child layers.  I need to get a list of groups and then iterate through the groups and delete them.  The original code is as follows:  legend = self.iface.legendInterface() group_names = legend.groups() rev = self.groups[:] rev.reverse() ...     for i, group in enumerate(rev):         legend.removeGroup(group)   I replaced self.iface.legendInterface() with QgsProject.instance().layerTreeRoot() but group_names = legend.groups() fails with the message 'QgsLayerTree' object has no attribute 'groups'   What is the proper container of the groups and how do I access the collection; and, once found, how do I delete those groups?  A search for information on how to remove groups from a layer tree in QGIS 3 has proven fruitless. Is it possible to skip releases during an upgrade? launch app, capture stdout and stderr in c++ How do I launch an app and capture the output via stdout and maybe stderr?  I am writing an automated build system and I need to capture the output to analyze. I'd like to update the svn repo and grab the revision number so I can move the files in autobuild/revNumber/ if successful. I also would like to build using make and upload the compile text to my server for everyone to see the warnings and errors on a failed build.  I can't find the system() function, but I found the CreateProcess() function on MSDN. I am able to launch what I need but I have no idea how to capture the stderr and stdout.  I notice the process launches separately unless I set a breakpoint and keep my app exiting which it then will keep all the text in my app console window. I would also want to wait until all processes are finished and then scan the data it produced to do any additional operations I need. How do I do any of this? Why does no line appear when using Interpolate Line in ArcMap? What is the motivation for including the compactness and semi-simplicity assumptions on the groups that one gauges to obtain Yang-Mills theories?  I'd think that these hypotheses lead to physically "nice" theories in some way, but I've never, even from a computational perspective. really given these assumptions much thought. How to remove blank lines from a file (including tab and spaces)? I want to remove all empty lines from a file. Even if the line contains spaces or tabs it should also be removed. Convert Month Number to Month Name Function in SQL I have months stored in SQL Server as 1,2,3,4,...12. I would like to display them as January,February etc. Is there a function in SQL Server like MonthName(1) = January? I am trying to avoid a CASE statement, if possible. How to defer variable expansion I was wanting to initialize some strings at the top of my script with variables that have no yet been set, such as:  str1='I went to ${PLACE} and saw ${EVENT}' str2='If you do ${ACTION} you will ${RESULT}'   and then later on PLACE, EVENT, ACTION, and RESULT will be set. I want to then be able to print my strings out with the variables expanded. Is my only option eval? This seems to work:  eval "echo ${str1}"   is this standard? is there a better way to do this? It would be nice to not run eval considering the variables could be anything. How to achieve a super leavened cake as the Pierre Herme ones? I made several cakes in my life. I know the difference between different leavening agents. I know that low temperature tends to make flatter cakes, but I never could get this kind of shape. If I use a super hot oven I burn the surface and I don't get this shape, there must be something else. Does anyone have experience doing this? Does anyone have a recipe from any modern pastry chef showing this kind of cake? Maybe gluten content in the flour could help?  Thank you diophantine equation: $x^2 +y^2 = z^n$ Prove that $x^2+y^2=z^n$ has a solution $(x, y, z)$ in $\mathbb{N}$ for all $n\in\mathbb{N}$  I tried to prove this by induction, but couldn't. ( This was probably because the solution for some $n$ isn't necessarily related to the solution for $n+1$)  I can't seem to see any other way other than induction for proving the statement. Any help/hints on solving this problem, or any alternative approach will be highly appreciated :) What is the lowest level of mathematics required in order to understand how encryption algorithms work? I have a database with millions of phone numbers with free-for-all formatting. Ie, the UI does not enforce any constraints and the users are typing in whatever they want.  What I'm looking for is a Java API that can make a best-effort to convert these into a consistent format. Ideally, the API would take the free text value and a country code and produce a valid international phone number or throw an exception.  For example, a phone number in the system might look like any of the following:  (555) 478-1123 555-478-1123     555.478.1123 5554781123   Given the country of US, the API would produce the value "+1 (555) 478-1123" for all these. The exact format does not matter, as long as it's consistent.  There are also numbers in the system without area codes, such as "478-1123". In that case, I would expect a NoAreaCodeException, or something similar.  There could also be data such as "abc", which should also throw exceptions.  Of course, there are countless variations of the examples I have posted, as well as the enormous complication of international phone numbers, which have quite complicated validation rules. This is why I would not consider rolling my own.  Has anyone seen such an API? Do I have to create vector files at the correct print size? Includegraphics maximum width With \includegraphics I can give the width of the resulting image (which would be scaled).   How can I give a maximum width of the image? That is, if the original is smaller than X, I'd like to keep the smaller image, if the image is larger than X, then the image width should be X.  Using pdflatex/graphicx. I have heard that most spam filters use a reverse DNS lookup on the originating IP address of the sending SMTP server (or something like that) as part of the verification process.  I want to make sure my emails will pass this check.  How exactly can I verify that my emails are OK?  In researching it, I've noticed that if I look at the header of a valid email message coming from Gmail, I will see something like this:  Received: from mail-pz0-f185.google.com (mail-pz0-f185.google.com [209.85.222.185])         by mx.google.com with ESMTP id 10si2346996pxi.164.2009.07.22.22.26.19;         Wed, 22 Jul 2009 22:26:19 -0700 (PDT)   When I do an nslookup on 209.85.222.18, it responds with mail-pz0-f185.google.com, which is what I would expect.  If it responded with a different domain, then I assume that would indicate a problem and it would fail the check.  Is this what the reverse DNS lookup is all about or am I barking up the wrong tree? The tutorial I read is based on 2.79. So I'm not sure if it's still the same name in 2.8. But I can't find anything providing similar functionalities. Supersymmetry in Quantum Field Theory I have an idea of supersymmetry in quantum mechanics, can you suggest a book on "supersymmetry in quantum field theory", which has sufficient mathematical rigour like "Peskin and Schroeder"