If the LaTeX strings are not intepreted in matplotlib (e.g., in the xlabel), check your configuration file
( see previous post for matplotlib configuration file).
You can either do it for one session :
rc('text', usetex=True) plot([1,2],[3,4]); title('a^2') |
or permanently within the matplolibrc by adding this line:
text.usetex : true |
Note 4/Sept/2013: the new location is /home/user/.config/matplotlib
If you have ipython, try this command
ipython -pylab |
and if you have Qt, you can change the backend (library used for plotting) and use qt as follows:
ipython -pylab qt |
Matploltib set up a special file called matplotlibrc, which can be found in the directory .matplotlib/ ( with a dot in front of it).
To locate your .matplotlib/ directory, use matplotlib.get_configdir():
>>> import matplotlib as mpl >>> mpl.get_configdir() '/home/user/.matplotlib' |
If you would like to use a different configuration directory, you can do so by specifying the location in your MPLCONFIGDIR environment variable
In order to fill the configuration file you will need to know the keywords. The full list is available here: http://matplotlib.org/users/customizing.html
The following example illustrates how to use R package with Python by using the Rpy2 package.
This problem solve in this example is to fit a normal distribution on some data samples.
from rpy2.robjects import r from rpy2.robjects.packages import importr rnorm = r('rnorm') # create an alias to the R function rnorm x = rnorm(n=1000, mean=0, sd=1) # generates the data sample (normal distribution) # load the MASS library for distribution fitting MASS = importr('MASS') params = MASS.fitdistr(x, 'normal') # perform the fitting here print params |
The result is stored in the variable params. The above code print the following results:
mean sd -0.07962739 1.00467570 ( 0.03177064) ( 0.02246523) |
Telling you that the distribution has mean of -0.08 and a standard deviation of 0. The bracketted numbers indicates how trustful are the results. Numbers in parentheses are confidence intervals around the parameter.
Lot of information is available in the Python documentation website: http://docs.python.org/library/profile.html . However, here is a small snapshot of how to use it :
Let us say you have a function call test(). First you need to run it:
import cProfile cProfile.run('from your_module import test; test()', 'prof') |
It will save profiling results in ‘prof’, which can then be parsed with pstats module:
import pstats p = pstats.Stats('fooprof') |
You can then introspect the data. For instance the following code sort the results by time and print the 10 largest one.
p.sort_stats('time').print_stats(10) |
Within VIM, there is a way to replace all the return carriage from Windows (that appear as ^M) by replacing them with the Linux version:
% s/^M/\r/g |
When \r stands for the return carriage in Linux (not \n as C users would expect) and ^M is not a concatenation of the characters ^ and M but a special character create by typing “Ctrl+V Enter” in VIM.
One reason to use SVN tool is to be able to revert to a previous version. How do we do that ?
Imagine that the latest version (the one on the HEAD) is not what you want anymore, but that the revision 13 is the good one. Just type:
svn merge -rHEAD:13 |
Commit the code, and you’ve go the code as it was at revision 13.
If you want to test some PHP code without using the browser interface, you can create a script to use command line shell as follows. Let us call this script scripting.php. Under Linux, create this file with the php extension and specify the executable path:
#!/usr/bin/php -q echo 'Hello'; |
Change the mode to executable:
chmod 755 scripting.php |
and run it :
./scripting.php |
It should work if your PHP is already well configured.
If you want to script R with arguments, you can type (under a Linux shell):
R --no-restore --no-save --args 10 < script.R |
where –args is a list of arguments that you want to use in your script. This script will contain the following commands:
args <- commandArgs(trailingOnly=TRUE) |
where trailingOnly means that commandArgs uses only the –args option so that you do not have to bother about the position of th –args argument.
The solution is to install gtk2-engines package:
sudo yum install gtk2-engines.i686 |
