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Speed up the loop operation in R
I have a big performance problem in R. I wrote a function that iterates over a data.frame object. It simply adds a new column to a data.frame and accumulates something. (simple operation). The data.frame has roughly 850K rows. My PC is still working (about 10h now) and I have no idea about the...
How Big can a Python List Get?
In Python, how big can a list get? I need a list of about 12000 elements. Will I still be able to run list methods such as sorting, etc?
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Select unique or distinct values from a list in UNIX shell script
I have a ksh script that returns a long list of values, newline separated, and I want to see only the unique/distinct values. It is possible to do this?
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How to use 'cp' command to exclude a specific directory?
I want to copy all files in a directory except some files in a specific sub-directory.
I have noticed that cp command didn't have the --exclude option.
So, how can I achieve this?
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John Carmack's Unusual Fast Inverse Square Root (Quake III)
John Carmack has a special function in the Quake III source code which calculates the inverse square root of a float, 4x faster than regular (float)(1.0/sqrt(x)) , including a strange 0x5f3759df constant. See the code below. Can someone explain line by line what exactly is going on here and why t...
How is the undo tree used in Vim?
This answer says:
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MySQL get row position in ORDER BY
With the following MySQL table:
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tmux set -g mouse-mode on doesn't work
I've been looking around and people say that putting
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AngularJS and its use of Dollar Variables
Does anyone know if the reasoning behind the use of dollar methods and variables in angularJS is to instruct angularJS to avoid checking those values when a digestion is going on? So, if angular comes across $scope.$value and $scope.value , then it will avoid checking the former since it's prefix...
How to debug a maven goal with intellij idea?
Can you debug a maven goal with Intellij IDEA? I know that I can right-click and run Debug . However, the maven plugin does not appear in my External Libraries list, so I can not go into the code and set a breakpoint. Thus, Debug runs through the goals without stopping, like Run does.
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