Re: index() function in the C++ API

[mpuglia]

To answer my own question, it looks something like this:

MArray<int> idx(dim_vector(20000,1));  //populate with indices in any order
idx_vector ind_vec_rows(':');
idx_vector ind_vec_cols(idx);
Matrix b = a.index(ind_vec_rows, ind_vec_cols);

And it's about 5x faster than using b.insert(a.column(i),0,i)) in a for
loop.

Does anyone know if there is way to access/assign the index values in the
ind_vec_cols vector?  This would be useful for reordering the ind_vector a
second time, rather than reordering the MArray and creating a new idx_vector
every time.  I can't find anything in the API that seems to do it though.






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