Re: [Matplotlib-users] plotting a matrix vs a vector

[John H. <jdh...@ac...>]

>>>>> "Ryan" == Ryan Krauss <rya...@co...> writes:

    Ryan>    Is there a quick and easy way to plot the columns of a
    Ryan> matrix versus a vector and get different color lines for
    Ryan> each column?  

You can build a color list and cycle through it with a counter, as
described in the recent thread "Plotting of multiple spectras" on the
mailing list.  Eg

 colors = ("b", "g", "r", "c", "m", "y", "k")
 ind = 1
 while ind < 18:
      Y = take(X,(0,ind), 1)
      x = Y[:,0]
      y = Y[:,1]
      plot(x,y,"-"+colors[ind % len(colors)])
      ind = ind + 2

    Ryan> line Do I need to define a matrix plotting function like def
    Ryan> matrixplot(xvect,ymat): ioff() for i in
    Ryan> range(shape(ymat)[1]): plot(xvect,ymat[:,i]) show() ion() or
    Ryan> is there an easier/faster way?  Ryan

Yes, this is one area in which the mpl plot function differs from
matlab.  There is a faster way, using line collections.  This
difference in speed would be considerable for a large number of
lines.  See examples/line_collections.py in matplotlib CVS.

JDH