Solving for scalar in matrix norm minimization

Is it possible in MATLAB to minimize argmin_alpha norm( X - alpha * Y , 1) (where X and Y are matrices)?
I want the following constraints:
alpha > 0, X - alpha * Y >= eps
Thanks

2 个评论

The thing you propose to minimize X - alpha * Y _1 is not a scalar. Do you mean you want to minimize some squared norm of this difference? If so, which norm? L2? Frobenius?
Sorry there was a problem with the text. This should be the matrix norm. The double bars were removed.

请先登录,再进行评论。

 采纳的回答

Matt J
Matt J 2014-9-4
编辑:Matt J 2014-9-4
If you have the Optimization Toolbox, you could also use fminimax, although that might be overkill for a simple scalar problem. Recall that the L1-norm of a matrix is its maximum absolute row sum.

1 个评论

Thank you.
I have that toolbox. fminbnd doesn't seem to be working, but I'll check out fminimax.

请先登录,再进行评论。

更多回答(1 个)

The system of linear inequalities
X(i) - alpha * Y(i) >= eps
are equivalent to some 1D interval [alpha_lower, alpha_upper]. Once you find this interval, you can apply fminbnd.
The analysis needed to find the interval is simple, but you could let this FEX file do it for you,

类别

Community Treasure Hunt

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

Start Hunting!

Translated by