## How to duplicate Matlab functionality

Since I am a total Matlab-n00b, I rather write a convoluted Python script instead of using the appropriate Matlab function. And here it is. A small script to compute the standard deviation of two vectors. I guess this would have been one Matlab command.

`import sys                                                                                                                                                                                       import scipy.io                                                                                                                                                                                  import math                                                                                                                                                                                                                                                                                                                                                                                      def computeStdDev(file, vec1, vec2):                                                                                                                                                                data = scipy.io.loadmat(file, struct_as_record=True)                                                                                                                                            vector1 = data[vec1]                                                                                                                                                                            vector2 = data[vec2]                                                                                                                                                                            if len(vector1) != len(vector2):                                                                                                                                                                    print "Error: Vectors do not have matching lengths."                                                                                                                                            return                                                                                                                                                                                      diff = vector1                                                                                                                                                                                  N = len(diff)                                                                                                                                                                                                                                                                                                                                                                                   for i in range(N):                                                                                                                                                                                  diff[i] = vector1[i] - vector2[i]                                                                                                                                                                                                                                                                                                                                                           mu = 0                                                                                                                                                                                          for val in diff:                                                                                                                                                                                    mu = mu + val                                                                                                                                                                               mu = mu / float(N)                                                                                                                                                                                                                                                                                                                                                                              sigma = 0                                                                                                                                                                                       for i in range(N):                                                                                                                                                                                  sigma = sigma + (diff[i] - mu)**2                                                                                                                                                           sigma = math.sqrt(sigma / float(N))                                                                                                                                                                                                                                                                                                                                                             print "mu: %f" % mu                                                                                                                                                                             print "sigma: %f" % sigma                                                                                                                                                                                                                                                                                                                                                                    if len(sys.argv) != 4:                                                                                                                                                                              print "Usage: %s file vector1 vector2" % sys.argv[0]                                                                                                                                            sys.exit(0)                                                                                                                                                                                                                                                                                                                                                                                  computeStdDev(sys.argv[1], sys.argv[2], sys.argv[3])                                                                                                                                             `

## Matlab and Python

How to read Matlab files with Python and SciPy can be read here. Short:

`import scipy.iodata = scipy.io.loadmat('test.mat')`

This will create a dictionary called data containing all the variables of the Matlab file.