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How does one reorder columns in a data frame?
... @user4050: you can also use df[,c(1,3,2,4:ncol(df))] when you don't know how many columns there are.
– arekolek
Mar 15 '16 at 14:28
1
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Node.js get file extension
... answered Apr 3 '13 at 3:32
SnowfishSnowfish
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/bin/sh: pushd: not found
...y my PS1 is (\u) \h:\w> but I just stripped it down to a generic string now for the answer. The prompt in DOS is also ending with > by default ($P$G IIRC), and I like that.
– hlovdal
Mar 4 '11 at 12:28
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Removing trailing newline character from fgets() input
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Perhaps the simplest solution uses one of my favorite little-known functions, strcspn():
buffer[strcspn(buffer, "\n")] = 0;
If you want it to also handle '\r' (say, if the stream is binary):
buffer[strcspn(buffer, "\r\n")] = 0; // works for LF, CR, CRLF, LFCR, ...
The function cou...
Merging dictionaries in C#
...ethod of course (with a better name, but I don't have time to think of one now) - it's not terribly hard to do, just overwriting (or ignoring) duplicate keys. The important bit (to my mind) is using SelectMany, and realising that a dictionary supports iteration over its key/value pairs.
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GitHub relative link in Markdown file
...les:
Starting today, GitHub supports relative links in markup files.
Now you can link directly between different documentation files, whether you view the documentation on GitHub itself, or locally, using a different markup renderer.
You want examples of link definitions and how they work...
How did Microsoft create assemblies that have circular references?
...to System.Xml.dll. After this, they compile System.Xml.dll the normal way. Now comes the magic. They recompile System.configuration.dll, with the part needing the reference to System.Xml.dll. Now there's a successful compilation with the circular reference.
In short:
A is compiled without the cod...
How do I use extern to share variables between source files?
I know that global variables in C sometimes have the extern keyword. What is an extern variable? What is the declaration like? What is its scope?
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Use Visual Studio web.config transform for debugging [duplicate]
...et-web-projects-web-debug-config-web-release-config/.
Here is the summary.
Now let’s see how we can enable what the question asker wants to do.
To recap, when he builds on a particular configuration he wants a specific transform to be applied to web.config. So obviously you do not want to maintain...
Why is processing a sorted array faster than processing an unsorted array?
... by Mecanismo, via Wikimedia Commons. Used under the CC-By-SA 3.0 license.
Now for the sake of argument, suppose this is back in the 1800s - before long distance or radio communication.
You are the operator of a junction and you hear a train coming. You have no idea which way it is supposed to go. Y...