Selecting cross values from two arrays

I have three arrays namely, s = [0,1000,2000], d = [0,1000,2000] and J = [0,5000,8000], where, J = 3*d+2000. Now within a for loop, when s(1) and d(1) are selected, I want to select J(1). When s(2),d(1) is selected, I want to select J(3). When s(2), d(2) is selected, I want to select J(2). What would be a generic way of doing this instead of hard coding?

[Raj]

Sorry but your question is not clear at all.

"when s(1) and d(1) are selected" - What do you mean by 'selected'? you want user to give selection inputs?

"I want to select J(1)" - You want J(1) to get computed here or you already have J matrix before 'for' loop and you want to select J(1) & do something with it?

[Mahesh Taparia]

Hi,

Can you explain what you want to do with these matrices, your doubt is not clear.

Answer 1

[KALYAN ACHARJYA]

Form the question, if you pattern the s,d, and J , it becomes

1 1 1
2 1 3
2 2 2

Have you find any pattern on the sequence? I dont think so...(one label condition)

Though you can do that by mutiple loops and condition statements, but direct implementation is much easier and faster here.

"What would be a generic way of doing this instead of hard coding?"

In addition, all vectors having 3 lengths only, you can do it by direct implementation, why do you think you have to go for "for loop" here.

Good Luck!

Answer 2

[Andrei Bobrov]

s = [0,1000,2000]; 
d = [0,1000,2000];  
J = [0,5000,8000];

ii = fullfact([3,3,3]);
out = [s(ii(:,1))',d(ii(:,2))',J(ii(:,3))'];

or

[ii,jj,k] = ndgrid(s,d,J);
out = [ii(:),jj(:),k(:)];