can you vectorize this?

[mansoor_]

   .

[Ciccioo]

something like...

create a vector V of size n

if a(i,i) = 0, then V(i) = 0, otherwise 1

transpose the matrix

multiply the matrix by V

transpose the result

 

i think it could even work

hope this is what you needed

[mansoor_]

something like...

create a vector V of size n

if a(i,i) = 0, then V(i) = 0, otherwise 1

transpose the matrix

multiply the matrix by V

transpose the result

 

i think it could even work

hope this is what you needed

 

i need to keep the rows, its a linear system, i want them to be arranged in a way such that the matrix has no zeros on it leading diagonal.

i think your solution would just delete the column.

[Ciccioo]

i need to keep the rows, its a linear system, i want them to be arranged in a way such that the matrix has no zeros on it leading diagonal.

i think your solution would just delete the column.

oh pardon, i misunderstood, i thought you needed to fill the row with zeroes

 

how would you choose the value to put where the zero is? (i have no idea how to read matlab code)

[mansoor_]

i dont want to replace values, if a row has a zero on the element which corresponds to the diagonal of the matrix then i need swap that row for one that doesnt have a zero there, also the row that i am replacing must not have a zero in the element in the leading diagonal of where it is to be moved to. 

[Flojer0]

You could create an identity matrix which has just ones along the diagonal and zeros everywhere else. Then find the rows in question with a simple boolean check and compress that into a list of your rows. like such:

identity = eye(n,n);    %Identity matrixidentity = identity == 0;    %Swap ones for zerosmat = a == identity;    %You now have ones anywhere there are zeros on the diagonalmat = max(mat,[],2);    %Now you have a single column with a one where it is needed

That is about as far as I'm getting right now, hopefully it helps.