Barry Smith wrote: > > Plus 1 for each row for the diagonal. > > Barry > > > On Nov 12, 2007, at 11:16 AM, Hong Zhang wrote: > >> >> >> On Mon, 12 Nov 2007, Zhifeng Sheng wrote: >> >>> Dear all >>> >>> my matrix is SeqSBAIJ with block size 1, so I am wondering when I >>> specify the nonzeros in a row, does it mean the actually nonzeros >>> numbers or the memory that is needed? (for instance, for SeqSBAIJ, >>> the actual nonzeros in a row would twice as much as memory needed) >> >> >> No, you specify the nonzeros of upper triangular part. >> >> Hong >> >>> >>> Thank you >>> Best regards >>> Zhifeng >>> >>> >> > Dear all
I allocated the memory exactly with symbolic computation, and tried preallocation on AIJ and SBAIJ, it works well for AIJ, no additional allocaiton is needed in assembly... then I did it on SBAIJ ( nonzeros of upper triangular part + 1), the performance is much worse , it seems that memory allocation was still needed... does anyone have such problem before? Thank you Best regards Zhifeng Sheng
