Re: [eigen] inf-norm of complex-matrix columns |

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Hi,
I think either
M.cwise().abs().colwise().maxCoeff();
or
M.cwise().abs2().colwise().maxCoeff().cwise().sqrt();
is what you want. With complex numbers, the latter version is probably faster
since it computes fewer square roots.
Martin
Am Donnerstag 03 Juni 2010, 21:21:38 schrieb Manoj Rajagopalan:
> Hi,
>
> Can someone help me come up with an expression to calculate the
> infinity-norm of the columns of a matrix, treated as vectors? I want to
> calculate the modulus of the complex entries in each column, and the
> maximum within that column. Therefore, my result should be a
> vector-expression whose length is the number of rows. In the following
> case, 4.
>
> MatrixXcd M(5,4);
> M.setRandom();
> M.colwise().?????
>
> Thanks,
> Manoj