Re: [Boost-Users] Re: uBLAS: reference to container data & iteratordeclaration

Hi,

...

Either use

matrix_column v (m.column (2)); // proxy[1]

or

vector<double> v (m.column (2)); // copy

Thank you so much. That seems to be exactly what I was looking for.

BTW.: It seems that "matrix_column c "can be used as a reference to any other 'vector-like' type, as the following also works:

c = v; // v beeing a vector; c = m.row(2); c = m.col(0);

Nope. You're overwriting the referenced part of the matrix three times now.

There is still an interesting point: While it is possible to assign a row to the matrix_column it is not possible to supply a row in the constructor call. What is the rationale behind this?

The constructor constructs the proxy, the assignment operator assigns to the proxied elements.

If the constructor also would accept a row I could use it as a parameter type for function calls when I want to express, that only 'data' types are expected and 'expressions' are not wanted. (Sorry for the sloppy formulation, I am not sure how to express this more concise.)

I hope, we'll be able to solve this, too. Best, Joerg