I have an equation $XA = B$ in which $X$ and $B$ are $n \times m$ and $A$ is $m \times m$. And $n>m$ . $A$ is positive definite. How to calculate $X$. I used $X = B / A$ in MATLAB. but it compute the warning that: Matrix is close to singular...
my question is that which matrix is close to singular? $A$ or $B$?
And My second is how to solve it by regularization?
I find some MATLAB toolbox solve those problem by regularization: https://www.mathworks.com/matlabcentral/fileexchange/52-regtools such as its function function [x_lambda,rho,eta] = tikhonov(U,s,V,b,lambda,x_0)
it solves $Ax = b$ But I don't know how to use it to $XA=B$.
Thanks