From a command prompt issue:
Furthermore where do I have to look if the %PATH% variable has a C:\Python26\ArcGIS10.0 entry?
echo %PATH%From a regedit session browse to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\EnvironmentOr probably best (because you can see both System and Current User values) select:
Start --> Computer --> Properties (System Properties) --> Advanced System Settings (Advanced tab) --> Environment VariablesThe Current User will have a Path -- just be sure if it has any Python related paths they do not conflict with the C:\Python26\ArcGIS10.0 location. And in the System Variables block that in the PATH listing, that C:\Python26\ArcGIS10.0 is the only listed Python--or at the least it must be the first listed.
Here is a sample pytplot script that should run displaying a Tcl/Tk plot from IDLE, PyWin32, IPython. It should run even in the ArcMap Python window (either enter each line or load it as a script).
If you can get it to run in IDLE and the ArcMap Python window you've fixed any path or configuration issues.
import numpy as np
import matplotlib.pyplot as plt
x = np.arange(0, 5, 0.1);
y = np.sin(x)
Syntax of the packages in your code is another issue.