Re: Sparse functions for octave

[John W. Eaton]

On 16-Nov-1999, A+A Adler <address@hidden> wrote:

| On Mon, 15 Nov 1999, John W. Eaton wrote:
| > Here's an example for the integer class defined in make_int.cc:
| >   octave_value_list
| >   octave_integer::do_index_op (int, const octave_value_list& idx)
| 
| Great, thanks. I've now got indexing working on sparse variables.

OK.  BTW, you *can* use the other function signature if you also
define an is_constant() function in your class that returns true.

| However in order to implement an efficient indexing algorithm,
| I need to sort the idx_vector, and then use the sort index
| to build the extracted matrix.
| 
| After digging around in /usr/local/include/octave/idx-vector.h,
| I found several methods on idx_vector which look promising.
| 
| I can use idx_vector::sort, but I need to get the sort index
| as well.
| 
| Could you explain if any of the methods on idx_vector allow
| this?

I don't think so.  It's not something that has come up before.  You'll
need to add a new method to the idx_vector class (and its internal
idx_vector_rep class) that do what you want.

jwe



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