Matrix inverse for non-square matrix

7 次查看（过去 30 天）
John Chesser
John Chesser 2019-4-11
编辑： John Chesser 2019-4-15
I am trying to create a code that solves viscoelastic mechanical behavior problems using the collocation method. In order to do this I need to solve the following;
[A]{D}={B} where is D is the array needing to be solved. Therefore {D}=[A]^-1 {B} where A is a (j x k) matrix and B is a (k x 1) array making the resulting D a (j x 1) array. In my current code j = 11 and k = 1,400,000. I've tried the following codes but the results are not correct;
Dj = pinv(Akj).*Bk;
However, this results in a k x j matrix for D.
and;
Dj = (Akj.^(-1))*Bk;
Which does result in the correct j x 1 array for D, but I do not believe it is given the correct values.
Thank you for your time.
  4 个评论
显示 2更早的评论
Christine Tobler
Christine Tobler 2019-4-15
I agree with David, probably the best would be to just use backslash.
Also, in your call
pinv(Akj).*Bk
the .* operator does an elementwise multiplication, not a matrix multiplication as you were probably intending.
The inv function errors for non-square matrices, so it should just not work, not give you any wrong results.
John Chesser
John Chesser 2019-4-15
编辑：John Chesser 2019-4-15
As mentioned above, A is supposed to be a (k x j) matrix. When filling A with it's values I had isssues in my loops which were causing A to be a (j x k) matrix. I have since fixed this and have implemented the suggested D = A\B, and it is working correctly and giving correct solutions. Thank you all for your help!

请先登录，再进行评论。

请先登录，再回答此问题。

回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Linear Algebra 的更多信息

标签

产品


版本

R2018a

Community Treasure Hunt

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

Start Hunting!

Translated by