how to do matrix addition of different sizes

E = diag([12:4:56])

B=rand(12,3)

C=A+B

Answer 1

[Azzi Abdelmalek]

C=A
C(:,1:3)=A(:,1:3)+B(:,1:3)

[krishnamurthy]

How to Calculate E

lambda=rand(1);

h-rand(1,12);

a=rand(1,12);

d=rand(1,12);

B=rand(12,3);

E=[(diag(a+(h.*d))./lambda)]+B;

[krishnamurthy]

sorry actually

 h=rand(1,12)

[Azzi Abdelmalek]

E1=diag(a+(h.*d))
E2=lambda+B;
E=E1
E(:,1:3)=E1(:,1:3)./E2(:,1:3)