How to assign values to a sparse matrix without iterations?

9 次查看（过去 30 天）

Benson Gou 2018-10-9

评论： dpb 2018-10-11

Hi, All,

I want to assign non-zero values to a matrix H. I know the locations of all the non-zeros. For example, I know the non-zero locations:

It indicates H(1,1)=1;H(1,2)=1;H(2,1)=1;H(2,5)=1;H(3,2)=1;H(3,3)=1;...

Would you please tell me how I can quickly assign this values without iterations?

Thanks a lot. Bei

Adam 2018-10-9

i = repmat( 1:size( Nonloc ), [1 2] );
j = Nonloc(:)
s = sparse( i, j, 1 );

Benson Gou 2018-10-10

Dear Adam,

Thanks a lot for your excellent code. It works very well.

Best regards, Bei

dpb 2018-10-9

S=sparse(Nonloc(:,1),Nonloc(:,2),1);

Benson Gou 2018-10-11

Hi, dab and Bruno,

Thanks for your comments. I think dab's code gives one "1" in each row while Adam gives two "1" in each row which is expected.

Thanks a lot again. Bei

dpb 2018-10-11

Ah! The light finally dawneth...the row isn't given but implied.

在 Help Center 和 File Exchange 中查找有关 Creating and Concatenating Matrices 的更多信息

Find the treasures in MATLAB Central and discover how the community can help you!

Translated by