Re: Finding circle from three points



> Firstly, let me say that I'm not a math god.
> I love math, I just don't do enough of it to be ANY good at it.

Not an issue.  If Maxima can help you, so much the better.

> > and with a little more manipulation, we get:
> This is supposed to be the solution for b, right ?

Sorry I wasn't clear.  That is the *numerator* of b.

By the way, determinants will help with systems of linear equations, but
these are not linear equations.

> a) What did length(sols) mean?  Is that Maxima speak?

Yes, Maxima has its own programming language.  I assigned the variable
"sols" to the list of solutions and then found the length of that list.

> What did you mean by 2 solutions? I'm assuming a real and
> imaginary solution because we've got an x^2 = 4 situation?

Yes.

> b) I assume rval, aval and bval are the r, a and b solutions to the
> problem ?

Yes.

> c) What does Part(sols[1],3) mean for example.

We assigned the variable 'sols' to the list of solutions.  sols[1] is
the first element of that list.  That is itself a list of the three
variable values, [a= ..., b= ..., r=...].  The third element of that
list is sols[1][3], with value "r=...".  That would have been clearer
than part(...,3), sorry.

In general, Maxima expressions are composed of parts.  If x is
[a=q,b=r,c=s], then x has three parts, named part(x,1), part(x,2), and
part(x,3). Part(x,3) is c=s, which in turn has two parts.  The first
part, part(x,1,1), is "c"; the second part, part(x,1,2), is "s".

There is both a tutorial and reference documentation attached to the
distribution.  Though like anything it could be improved, I think it's a
good starting point.

    -s

PS I'm happy to help on this mailing list, but if you need more
extensive help, I am also available for consulting.