using FindRoot with a list of starting values
- To: mathgroup at smc.vnet.net
- Subject: [mg25757] using FindRoot with a list of starting values
- From: "Lu, Shihua" <SLu at crai.com>
- Date: Sat, 21 Oct 2000 14:43:10 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Here is the problem. I need to solve a simultaneous equation system using
FindRoot. For example, there are 3 equations and 3 unknowns,
FindRoot[{eq1, eq2, eq3},{x,x0},{y,y0},{z,z0}]
However, when I have many unknowns, it is awkward to type in all the
starting values by hand. Also, if I need to change the starting values in
the middle of the program, or even change the number of unknowns to solve
for, I need to find out a more elegant way to provide inputs to FindRoot.
I tried the following. First, I built a list,
start={{x,x0},{y,y0},{z,z0}}.
Then, I use the command
FindRoot[{eq1,eq2,eq3},start].
It did not work because start is a Table.
Can someone teach me a trick to make it work?
Many thanks,
Shihua Lu