Re: uBLAS: reference to container data & iteratordeclaration

From: speedsnaii (speedsnaii_at_[hidden])
Date: 2003-03-05 03:24:25

> 
> Either use
> 
> matrix_column<matrix<double> > 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<matrix<T> > 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);

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?

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.)

> > *) Second question:
...

> matrix_column<matrix<double> >::iterator it;

This is clear to me now. I've RTFM'd ;-) and found the example using 
the free column() functions. 

Roland