[Sussex] Help! Equation for a surface wantted.

[Steve Dobson]

Hi anyone who is good at maths

I'm looking for the equation of a surface (Cartesian form).  It
is like a torus which I would define thus:

   pow(c - sqrt(pow(x,2) + pow(y,2)), 2) + pow(z,2) - pow(a,2) = 0

   where:
      pow(a, b) - raise a to the power b, and
      sqrt(a)   - gives the positive square root of a

This gives a torus where the circle (radius a) is rotated around
the Z axis at a distance c.

The surface I want is very similar to a torus, but the radius of
the circle changes linearly between two values.

Ta
Steve
-- 
Debian Tip of the E-Mail:
Debian Hint #25: If you would like to thank a maintainer for handling an
issue, check out reportbug --kudos.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://mailman.lug.org.uk/pipermail/sussex/attachments/20051020/8b1f55b4/attachment.pgp