Plotting histograms

[Robert Kern]

amitsoni.1984 at gmail.com wrote:
> Thanks Robert,
> 
> My previous problem is solved(I was using 'from matplotlib.pylab import
> *') but now I am facing another problem. I want to plot the histogram
> of eigenvalues calculated and I am using the following code:
> _______________________________________________________________________
> import numpy
> from matplotlib import pylab
> 
> n=100
> ra = numpy.random
> la = numpy.linalg
> 
> A = ra.standard_normal((n,n))
> S = (A + numpy.transpose(A))/(2*n^(1/2))

Note that this line won't do what you think it does. First, one integer divided 
by another integer returns an integer, so (1/2) == 0. Also, ^ is not 
exponentiation but bitwise XOR. Use ** for exponentiation. However, in this 
case, you should use numpy.sqrt().

> eig = la.eigvals(S)
> 
> [N,x]=pylab.hist(eig, 10) # make a histogram
> -------------------------------------------------------------------------------------------------------------
> 
> But again it is giving some error, which is given below:
> 
> File "C:\Documents and Settings\amitsoni\Desktop\New
> Folder\wignerpython", line 15, in <module>
> [N,x]=pylab.hist(eig, 10) # make a histogram
> ValueError: too many values to unpack
> 
> Can anyone help me out with this??

pylab.hist() does not return two values, it returns three. Sorry I didn't catch 
that earlier.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco