How to speed up my code (computing jacobian)

My input are a lot of linear expressions such as x1+x2, x2+3*x3 etc. How to speed up my code as follows

allvars = symvar(input); % There are about 1000 LINEAR expressions in 'input'

J = jacobian(input, allvars);

[Torsten]

You shouldn't work symbolically with about 1000 expressions. A numerical approach is the way to go.

[M. Wang]

Thanks for your advice! Is there any approach without loss of precision?

Answer 1

[Matt J]

You can use equationsToMatrix to obtain the Jacobian. Depending on what you are doing, you might then convert the matrix to double so you can reuse and do more rapid numerical manipulations with it.

[Torsten]

Assuming that "input" only consists of linear expressions, not only a lot.