Vpasolve and indeterminate system

5 views (last 30 days)
Eve_B
Eve_B on 16 Jan 2019
Answered: Walter Roberson on 16 Jan 2019
Hello,
I have an indeterminate systemm, AX=B, which means that solutions exist but A does not have full column rank, it is singular. Is it posiible to use vpasolve to obtain some solutions in this case, even though there will be an indeterminacy of some constants?
Thank you!

Answers (2)

Star Strider
Star Strider on 16 Jan 2019
The vpasolve function may not be your best option.
See if the lsqr (link) function will do what you want. It’s intended for sparse matrices. It can also works iwth singular matrices.

Walter Roberson
Walter Roberson on 16 Jan 2019
If solutions do exist then even if the system is underdetermined, vpasolve() can potentially solve it. If you needed multiple solutions you could either try the 'random' option or you could carefully supply search ranges, executing multiple times with one of the variables constrained to different ranges, to try to find multiple solutions relative to that variable.

Categories

Find more on Numerical Integration and Differential Equations in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!