backward recurssion in a loop

Hi!

I would be grateful if anyone could help me with something similar to the following problem.

if

I have a matrix A=rand(n,a)

where n=9 and a=20

I have B=rand(1, 20)

I need to solve for C (n, a) which has to be solved backwards using A and B. The last row of C can be obtained by subtracting the last row of A from B. So, C(9,:)=B-A(9,:).

C(n-1,:) can be recovered by backward recurrsion so Now C(8, :)=C(9,:)-A(8,:) similarly C(7,:)=C(8,:)-A(8,:) and so forth and so on up to C(1,:)=C(2:)-A(2,:).

Can someone help with how can this be iterated in a loop?

Answer 1

[David Hill]

c=zeros(9,20);
c(9,:)=b(9,:)-a(9,:);
for i=8:-1:1
    c(i,:)=c(i+1,:)-a(i,:);
end

[Z.khan]

Thanks a lot David.