title: why does numrow>numcol for PCA in matplotlib
body: <p>I have 15 data sets all with 62 points of information and im trying to do a pca analysis of them, every point in the first data set corresponds to same point in the second and third etc. However at the moment my code, see bellow, produces the meansa value over the 62 points not the 15, i have only included 3 in the code. why when i swap x and y in the array does it say 'we assume data in a is organized with numrows>numcols'. What could I do to change this? here is my code.</p>
  
  <pre><code>import numpy as np
  import matplotlib
  from matplotlib.mlab import PCA
  
  x=np.zeros((62,3))
  a=np.genfromtxt('1.txt').T[2] #list 62numbers
  x[:,0]=a
  print x[:,0]
  b=np.genfromtxt('2.txt').T[2] #list 62numbers
  x[:,1]=b
  c=np.genfromtxt('3.txt').T[2] #list 62numbers
  x[:,2]=c
  results=PCA(x)
  print results.mu
  </code></pre>