清空筛选条件
清空筛选条件

numjac on a subset of variables

47 次查看（过去 30 天）
Riccardo
Riccardo 2015-2-20
回答： Vinh Nguyen 2017-5-2
I want to calculate the numerical Jacobian of my system using numjac.
It works fine with the regular syntax:
[Jac, FAC] = numjac(@(t,y)model(t,y,X,VAR),ttot,ytot',dydt,jac_tol,FAC);
However I don't need the full jacobian, but only the derivatives with respect to some y's. I can calculate the full one then select the needed lines, but it is a waste of computational time. How can I calculate the jacobian only where I need it?

请先登录，再回答此问题。

回答（1 个）

Vinh Nguyen
Vinh Nguyen 2017-5-2
I think you can do that by providing the Jacobian Structure. You can set the Jacobian Structure element 0 or 1. 1 for the derivatives respective to your variables you need.

类别

在 Help Center 和 File Exchange 中查找有关 Systems of Nonlinear Equations 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by