Hello math fans...

I still seem to have difficulties making myself undersood.
A too long time since school and the lack of proper english
mathematic vocabulary aren't helping ;-)

So, here we go for another try:

Stephen Lavedas wrote in message <35E85E76.CC135024@Ragingbull.com>...
>A ellipse has the formula (in two dimensions) x^2/a^2 + y^2/b^2 = c^2
>where the major axis is a or b depending on which is larger.

...hmm, let me see... it seems that... hmm... yes... ...
er... I'll need that book... thank you... and, er... that one too...

x^2/a^2 + y^2/b^2 = c^2 surely is an ellipse... but of axis 2*a*c and
2*b*c. You surely meant x^2/a^2 + y^2/b^2 = 1.

This ellispse has its center (the intersection of the two axis) at <0,0> and
two focii (I do not know their coordinates, but this doesn't matter here).

x^2/a^2 + y^2/b^2 = 1 is the cartesian equation (in rectangular
coordinates) of the ellipse. The pair of trigonometric equations
I tried was the parametric equation (in rectangular coordinates)
and is equivalent to the cartesian one (they describe the same
shape).

... or so I believe, but I can of course be wrong.

>Anyhow...question for you... where is the center of the torus you use in
>relation to the boxes?

That's a part of what I am trying to solve. Given: (in plane) two points
their tangents; unknown an ellipse (center and two half-axis). The
system of six equations for six unknowns led me to believe that it can
be done without the rotation of the cylinder. But maybe the system is
unsolvable this way and you really need the rotation. My purpose
would be defeated if this was the case.

>However if you send me some source I could be more helpful...
>(feel free to email it to me)

I can't: I am writing macros to do linear mouldings as well as collumns
relief, so I am after a general solution. But if you want, I can post or
email what I have already done. The file isn't very long, but is written
in a kind of franglais, with architectural terms my dictionnary can't
translate.



Thank you again for your help,

Thruthfully,


Philippe

Post a reply to this message