Plot Intrinsic Equations Free with KmPLot and Maxima

[Fermat]

Anyone know of a program/application/applet that will plot/graph intrinsic equations ?
(preferably free)

I've already had suggestions for KmPLot and Maxima, but neither, it seems, can do the job.
KmPLot is mainly for Linux and I'm on Win XP. (also Vista)

 

[trebmling]

Try Origin, it's the best for this. But it is not free.

 

[Fermat]

Thanks. I've downloaded the evaluation copy. But I can't find any reference to "intrinsic" in the help files.. There's nothing in the plot menu about intrinsic equations either.

The intrinsic equaion for the parabola is,

s = a tan(psi) sec(psi) + a log(tan(psi)+sec(psi)).

How would I use Origin to plot this?

TIA

 

[trebmling]

create new graph
go to menu Graph/add function graph/then copy-paste your equations, or use the drop down menu to choose elementary functions to combine them into your formula.

And they have an excellent forum there http://www.originlab.com/forum/default.asp

 

[Fermat]

Thanks for the input Trebmling, but I'm wondering if we have been talking at cross purposes.

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.)

I've been to the Origin forum and posted my query there - "how do I use Origin to plot an intrinsic equation?" - using the above description of an intrinsic eqn. I've had no responses.

I can go into Origin, create a new graph, and give a function, which will be F(x)=cos(x), say - a Cartesian equn. I can tell Origin to treat this as a polar eqn. But can I tell Origin to treat it as an intrinsic equation?

This is what I still can't get.