The latest additions to this site include a link (What are TeX and its Friends?) to the LaTeX page and the latest in sagetex plotting (added to the Plotting with Sagetex page). That plotting template solves the problem of scaled axes. It doesn't work with the Altermundus packages. My experimentation with using Sage as the plotting engine has demonstrated:

**For best results use sagetex with pgfplots**- \sagestr should be used to insert the entire tikzpicture environment into the LaTeX document (rather than inserting some plot data into an already defined tikzpicture environment)

The latest template combines the look and feel of the template here along with ability to scale the axes--see that post for a little more information about the plotting parameters. You can see in the screenshot that the y axis has been compressed to half its normal length. In this latest template I've used Sage to plot the function, calculate it's derivative at a point and use that derivative in plotting the tangent. The template can be downloaded on the Plotting with Sagetex page.