# Grapher for intrinsic equations

1. Jan 29, 2009

### Fermat

I'm looking for a program/application/applet that will plot for me intrinsic equations. I've posted this question a couple of times and had responses, but also misdirections, and so I include a definition.

An intrinsic equation, of the form s=f(psi), passes through the origin. s is the distance along the curve from the origin to a point of interest and psi (or tan(psi)) is the slope of the curve at the point of interest. (In other words, s and psi are not rectangular/Cartesian coordinates, or polar coordinates.)

Suggestions I've had include Kmplot, Maxima and Origin. I couldn't find a download for Kmplot (I'm on XP) and Maxima and Origin only seemed to have Cartesian or polar equations.

Intrinsic equations are also known as natural equations.

TIA