'Double' FindRoot
- To: mathgroup at smc.vnet.net
- Subject: [mg8690] 'Double' FindRoot
- From: Michaela Meier <michaela.j.meier at rz.ruhr-uni-bochum.de>
- Date: Mon, 15 Sep 1997 02:49:16 -0400
- Organization: Ruhr-Uni-Bochum
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
I've got another serious problem
I'm trying to find a numerical solution to a set of three equations:
1)
FindRoot[
{fa[0.1,x1]==fa[x2,x3],
fb[0.1,x1]==fb[x2,x3],
fc[0.1,x1]==fc[x2,x3]},
{x1,0.1},{x2,0.1},{x3,0.9}]
Worst of all: fa, fb, and fc are defined as:
(this is a simplified example !)
2)
fa=Function[{y1,y2},
fr=FindRoot[
{a1 x + b1 y + c1 z == p1[y1,y2],
a2 x + b2 y + c2 z == p2[y1,y2],
a3 x + b3 y + c3 z == p3[y1,y2]},
{x,0.1},{y,0.1},{z,0.1}];
x + y + z /. fr
]
Just typing 'fa[1,2]' produces NO error.
But as soon as I start program 1) Mathematica says that it's expecting a
'list of length 3'
Again: If I calculate 'fa' all by itself it returns a number for all
combinations of y1 and y2
So what causes this error ?? Or isn't Mathematica able to do more than
one FindRoot at the same time ????
Michaela