about popen and gnuplot

[yoast]

dear all,
	i have a question about popen and gnuplot.
	i got an example from ASPN, used to drive gnuplot with python 
on __win32___  platform. the code looks like below.

import os
f=os.popen('d:/xxx/pgnuplot.exe', 'w')
print >>f, "p sin(x)"
f.flush()

	i can see the gnuplot's interactive window, but can't
see the plot window. why? what should be done to make it
work? i see the code of gnuplot.py (a sourceforge project),
the code in that script is absolutely same as mine :(

best regards,
yoast at whu.edu.cn
3.24