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Set default CRAN mirror permanent in R
...tilde expansion). If this variable is
unset, the default is R_HOME/etc/Rprofile.site, which is used if
it exists (which it does not in a 'factory-fresh' installation).
So do Sys.getenv("R_PROFILE") for the first option, or Sys.getenv("R_HOME") or R.home() for the second option. On m...
How expensive is RTTI?
...
if (typeid(a) == typeid(b)) {
B* ba = static_cast<B*>(&a);
etc;
}
instead of
B* ba = dynamic_cast<B*>(&a);
if (ba) {
etc;
}
The former involves only one comparison of std::type_info; the latter necessarily involves traversing an inheritance tree plus comparisons.
P...
Where is PHP.ini in Mac OS X Lion? Thought it was in /usr/local/php5/lib
... on my Mac, uncommented httpd.conf, activated web sharing, installed MySQL etc.
I can't seem to find my PHP files, most importantly, PHP.ini.
...
For homebrew mysql installs, where's my.cnf?
... you want to create your own my.cnf to override any defaults, place it at /etc/my.cnf.
Also, you can run mysql --help and look through it for the conf locations listed.
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf
Th...
How to set the environmental variable LD_LIBRARY_PATH in linux
...le under Ubuntu the right way to do this is to add a custom .conf file to /etc/ld.so.conf.d, for example
sudo gedit /etc/ld.so.conf.d/randomLibs.conf
inside the file you are supposed to write the complete path to the directory that contains all the libraries that you wish to add to the system, fo...
java.net.ConnectException: Connection refused
...to work out exactly how far the data's getting. Look at your firewall logs etc.
– Jon Skeet
Sep 30 '12 at 17:53
@JonSk...
Is Using .NET 4.0 Tuples in my C# Code a Poor Design Decision?
...hat case, rather than having to remember the significance of Item1, Item2, etc.
Anonymous classes in C# already provide a superb solution to the most common private use of tuples, and they give meaningful names to the items, so they are actually superior in that sense. The only problem is that they...
How to use a variable inside a regular expression?
...(TEXTO) + r"\b(?!\w)"
if re.search(my_regex, subject, re.IGNORECASE):
etc.
Note the use of re.escape so that if your text has special characters, they won't be interpreted as such.
share
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im...
What is the difference between a “function” and a “procedure”?
...does not change the state of the system.)
Thus, rand() or print("Hello"), etc. are not functions but procedures.
While sqrt(2.0) should be a function: there is no observable effect or state change no matter how often one calls it and it returns always 1.41 and some.
...
Sending a message to nil in Objective-C
...ically zeroed. So design you API so that it can respond to 0/nil/NIL/NULL etc.
– Cthutu
Mar 21 '12 at 18:28
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