[petsc-users] how to use MatSetValues?

[Gianluca Meneghello]

I think m and n are the number of rows and columns you are inserting
in the matrix. If you insert one value at a time, that would be

MatSetValues(xx,1,row,1,col,val,INSERT_VALUES);

I hope it helps

Gianluca

On 8 March 2011 09:39, Tomasz Jankowski <tomjan at jay.au.poznan.pl> wrote:
> hello,
>
> Could someone give me a hand with MatSetValues function?
>
> suppose such example sparse matrix
>
> 0   1.1 0   0   0
> 2.2 0   0   0   0
> 0   0   0   0   3.3
> 0   0   4.4 0   0
> 0   0   0   5.5 0
>
> after storing it in row, col and val arrays we have
>
> row[0] = 0;col[0]=1;val[0]=1.1;
> row[1] = 1;col[1]=0;val[1]=2.2;
> row[2] = 2;col[2]=4;val[2]=3.3;
> row[3] = 3;col[3]=2;val[3]=4.4;
> row[3] = 4;col[3]=3;val[4]=5.5;
>
> question is: how to use MatSetValues with it?
>
> I thought that 'MatSetValues(xx,5,row,1,col,val,INSERT_VALUES);' would be
> good but it doesn't .(I suppose I don't fully anderstand how it works...)
>
> thanks,
>
> tom
>
> ########################################################
> #               tomjan at jay.au.poznan.pl                #
> #              jay.au.poznan.pl/~tomjan/               #
> ########################################################
>



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