Obtaining a sub-matrix based on some condition

Hello, I have a 10*3 matrix. 1st column represents Type of load(T), 2nd & 3rd are active(P) and Reactive (Q) Power loads. T columns contains 1, 2, 3 numbering indicating residential, commerial and industrial type of load.

Now, i just want a P and Q column such that if T=1, i wanted to multiply corresponding row of P & Q values with 3, similary if T=2 (and T=3), i wanted to multiply corresponding row of P & Q with 5 and 7 respectively. finally, i want a matrix 10*2, which contains only P&Q columns. i have attached document for better understanding. Please help me in this regards.

Answer 1

[KSSV]

L = [1 2 1 3 3 3 1 3 1 2 ;400 40 90 80 55 45 35 40 30 20 ; 60 30 0 15 55 0 30 30 15 20]';

iwant = zeros(size(L)) ;

idx = unique(L(:,1)) ;
Val = [3 5 7] ;
for i = 1:length(idx)
    pos = L(:,1)==idx(i) ;
    iwant(pos,:) = [L(pos,1) Val(i)*L(pos,2) Val(i)*L(pos,3)] ;
end

[Raghavendra Reddy P]

Hello Sir, Thanks for the your speedy response. Am facing some error in the statement below. my file name is loadvary

Error in loadvary (line 30) iwant(pos,:) = [L(pos,1) Val(i)*L(pos,2) Val(i)*L(pos,3)]

[Raghavendra Reddy P]

Attempted to access Val(4); index out of bounds because numel(Val)=3.

Error in loadvary (line 30) iwant(pos,:) = [L(pos,1) Val(i)*L(pos,2) Val(i)*L(pos,3)]

[Raghavendra Reddy P]

Sir, Thank you. I got it. your answer was right. there was some mistake with my matrix. :)