On 4/1/07, Kostas Oikonomou <ko at research.att.com> wrote:
> However, I don't think we have a consistency problem here
First of all, there's the issue of parameters vs. variables, which I
mentioned in a recent email (but after your last email).
Secondly, there is in fact a consistency problem here because r1..c3
have a constraint on them.
Given
eqs: [r(1)=r1,r(2)=r2,r(3)=r3, c(1)=c1,c(2)=c2,c(3)=c3]$
let's eliminate the x[i,j]'s:
eliminate(eqs,[x[1,1],x[1,2],x[1,3],x[2,1],x[2,2]]);
eliminate(%,[x[3,1]]);
=> [ - r3 - r2 - r1 + c3 + c2 + c1 ]
(It doesn't work to combine the variable lists; I'm not sure why...)
So there is a constraint on the parameters. Let's incorporate the constraint:
solve( subst( r3 = - r2 - r1 + c3 + c2 + c1, eqs),
[
x[1,1],x[2,1],x[3,1],x[1,2],x[2,2],x[3,2],x[1,3],x[2,3],x[3,3] ] ) =>
[[
x[1,1] = -r2+c1+%r18-%r17+%r16,
x[2,1] = r2-%r18-%r16,
x[3,1] = %r17,
x[1,2] = r2+r1-c3-c1-%r18+%r17+%r15,
x[2,2] = %r18,
x[3,2] = -r2-r1+c3+c2+c1-%r17-%r15,
x[1,3] = c3-%r16-%r15,
x[2,3] = %r16,
x[3,3] = %r15
]]
Does that help?
-s