[Gnuplot-py-users] Broken Pipe when plotting 3D data

I am trying to figure out how to plot 3D data.  I began with the script "
demo.py" that comes with the gnuplot-py distribution.  I am only changing
what function is plotted but I get the error copied at the end of this
email.  I am using just a minimal script (also copied below).  The formula
for m which is commented out does not work, but the current formula for m
does work.  Can someone help me understand what the problem is?

Thanks,

Jeremy



import scipy
import Gnuplot

def main():
    x = scipy.arange(35)/2.0
    y = scipy.arange(30)/10.0-1.5
    xdat = x[:,None]
    ydat = y[None,:]
    m = (scipy.sin(xdat) + 0.1*xdat) - ydat**2
#   m = scipy.sin(scipy.sqrt(xdat**2+ydat**2))/scipy.sqrt(xdat**2+ydat**2)
    print "len(x): %s" %len(x)
    print "len(y): %s" %len(y)
    print "len(m): %s" %len(m)
    dat = Gnuplot.GridData(m,x,y, binary=0)

    Chart = Gnuplot.Gnuplot(debug=1)
    Chart('set pm3d')
    Chart('set parametric')
    Chart('set data style lines')
    Chart('set hidden')
    Chart('set contour base')
    Chart.splot(dat)


main()


python learnGnuplot.py
len(x): 35
len(y): 30
len(m): 35
gnuplot> set terminal aqua
gnuplot> set parametric
gnuplot> set data style lines
gnuplot> splot "/tmp/tmpf2ZHuU.gnuplot/fifo" notitle

gnuplot> splot "/tmp/tmpf2ZHuU.gnuplot/fifo" notitle
               ^
         line 0: 2 columns only possible with explicit pm3d style (line 16)

Exception in thread FIFO Writer for /tmp/tmpf2ZHuU.gnuplot/fifo:
Traceback (most recent call last):
  File
"/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/threading.py",
line 460, in __bootstrap
    self.run()
  File
"/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/Gnuplot/PlotItems.py",
line 448, in run
    f.write(self.content)
IOError: [Errno 32] Broken pipe