I have a matrix which size is mxm (square) variable and I wanna assign a mx1 matrix into the first matrix's diagonal. What kind of loop I have to write?

2 次查看（过去 30 天）

sermet 2013-5-19

for example;

%m=matrix's row which is variable depends on the input

a=zeros(m)

b=[mx1]

I wanna assign b matrix into the a matrix's diagonal.

sermet 2013-5-19

a=[0 0 0;0 0 0;0 0 0]

b=[1 2 3]

c=[1 0 0;0 2 0;0 0 3] I wanna create c matrix which its diagonal belongs to b

Image Analyst 2013-5-19

I was going to suggest the cyclist's third method, which he posted before your comment above. Did you try it?

the cyclist 2013-5-19

编辑：the cyclist 2013-5-19

This is very easy, if the off-diagonal element are always zeros:

m = 5;
b = rand(m,1);
a = diag(b);

But if you want a more general way to insert b along the diagonal of any array a, then here's one way:

m = 5;
% Set up the array and vector:
a = magic(m);
b = rand(m,1);
% Insert vector into main diagonal of array
a(1:m+1:end) = b;

Another way to do the last step is:

a(logical(eye(m))) = b;

sermet 2013-5-19

thank you so much

MATLAB Mathematics Linear Algebra

在 Help Center 和 File Exchange 中查找有关 Linear Algebra 的更多信息

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

Translated by