[Starpu-devel] BCSR: the rowptr field.

[Cyril Roelandt <cyril.roelandt@inria.fr>]

Hey !

I'm currently rewriting the BCSR test, and I have some trouble filling 
the rowptr field of the starpu_bcsr_interface structure. I want to use 
the following matrix :

0 1 0 0
2 3 0 0
4 5 8 9
6 7 10 11

with c = r = 2.

nzval is obviously :
[ 0, 1, 2, 3] (upper left block)
  4, 5, 6, 7, (lower left block)
  8, 9, 10, 11] (lower right block)

I think colind should be [0, 0, 2], since the first two blocks start at 
column 0, and the lower right block starts at column 2.

But I'm not sure of what should be put in the rowptr field. Does anyone 
master the BCSR format ?

Note that I could use fake values, since the test just makes sure that 
copying data from a device to another works. Still, I'd like to use 
meaningful values, so that the test can serve as an example of the use 
of the BCSR interface (I don't think we have any code using this 
interface in examples/).


Cyril.