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Dynamically select data frame columns using $ and a character value
I have a vector of different column names and I want to be able to loop over each of them to extract that column from a data.frame. For example, consider the data set mtcars and some variable names stored in a character vector cols . When I try to select a variable from mtcars using a dynamic s...
MySQL - Get row number on select
Can I run a select statement and get the row number if the items are sorted?
5 Answers
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is it possible to change values of the array when doing foreach in javascript?
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The callback is passed the element, the index, and the array itself.
arr.forEach(function(part, index, theArray) {
theArray[index] = "hello world";
});
edit — as noted in a comment, the .forEach() function can take a second argument, which will be used as the value...
Using Chrome's Element Inspector in Print Preview Mode?
I am working on developing a website and need to work on the print view. Typically when I have layout issues I use Chrome's Element Inspector. However this does not exist in print preview mode.
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What is a bank conflict? (Doing Cuda/OpenCL programming)
I have been reading the programming guide for CUDA and OpenCL, and I cannot figure out what a bank conflict is. They just sort of dive into how to solve the problem without elaborating on the subject itself. Can anybody help me understand it? I have no preference if the help is in the context of CUD...
git selective revert local changes from a file
...t -m "tmp"
Now you have a commit with only the changes you want to keep, and the rest is unstaged.
git reset --hard HEAD
At this point, uncommitted changes have been discarded, so you have a clean working directory, with the changes you want to keep committed on top.
git reset --mixed HEAD^
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Why does Pycharm's inspector complain about “d = {}”?
... a shame because it is useful for many things like PEP, ..., real problems and real performance hints.
– dashesy
Jan 14 '15 at 18:09
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Is there a way to use PhantomJS in Python?
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This worked beautifully, and probably saved me days. Thank you. If one wants the whole rendered page back as source, it's driver.page_source.
– scharfmn
Apr 12 '13 at 15:12
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How to limit setAccessible to only “legitimate” uses?
...UT THIS???
That depends entirely on what types of programs you're writing and for what kind of an architecture.
If you're distributing a software component called foo.jar to the people of the world, you're completely at their mercy anyway. They could modify the class definitions inside your .jar (...
Unix command to find lines common in two files
I'm sure I once found a unix command which could print the common lines from two or more files, does anyone know its name? It was much simpler than diff .
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