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What's the fastest way to merge/join data.frames in R?
...he first example sqldf is 3x slower than data.table and in the second its 200x faster than plyr and 100 times faster than data.table. Below we show the input code, the output timings for the merge and the output timings for the aggregate. Its also worthwhile noting that sqldf is based on a databa...
How to take column-slices of dataframe in pandas
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Generate colors between red and green for a power meter?
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203
This should work - just linearly scale the red and green values. Assuming your max red/green/bl...
How to pip install a package with min and max version range?
...to install a package with both a minimum version ( pip install package>=0.2 ) and a maximum version which should never be installed (theoretical api: pip install package<0.3 ).
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Best Practice: Software Versioning [closed]
...n to the outside world.
So If you make a major change move from version 1.0.0.0 to version 2.0.0.0 (you changed from WinForms to WPF for example). If you make a smaller change move from 1.0.0.0 to 1.1.0.0 (you added support for png files). If you make a minor change then go from 1.0.0.0 to 1.0.1.0 ...
How can I scale the content of an iframe?
...ra and Safari if you change the CSS to:
<style>
#wrap { width: 600px; height: 390px; padding: 0; overflow: hidden; }
#frame { width: 800px; height: 520px; border: 1px solid black; }
#frame {
-ms-zoom: 0.75;
-moz-transform: scale(0.75);
-moz-transform-origin...
Why `null >= 0 && null
...ncrements the value of a variable by 1 if its type is number and assigns 0 to the variable if not, where the variable is initially null or undefined .
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mfc里面的140种颜色宏 - C/C++ - 清泛网 - 专注C/C++及内核技术
mfc里面的140种颜色宏MFC编码是需要配色的，可以参考使用。#pragma once #define CLR_LIGHTPINK RGB(255, 182, 193) ...mfc编码时需要配色的，可以参考使用。
#pragma once
#define CLR_LIGHTPINK RGB(255, 182, 193) // 浅粉红
#...
What is the smallest possible valid PDF?
...ting problem. Taking it by the book, you can start off with this:
%PDF-1.0
1 0 obj<</Type/Catalog/Pages 2 0 R>>endobj 2 0 obj<</Type/Pages/Kids[3 0 R]/Count 1>>endobj 3 0 obj<</Type/Page/MediaBox[0 0 3 3]>>endobj
xref
0 4
0000000000 65535 f
0000000010 00000 n
00...
How do we control web page caching, across all browsers?
...che-Control: no-cache, no-store, must-revalidate
Pragma: no-cache
Expires: 0
The Cache-Control is per the HTTP 1.1 spec for clients and proxies (and implicitly required by some clients next to Expires). The Pragma is per the HTTP 1.0 spec for prehistoric clients. The Expires is per the HTTP 1.0 an...