How do I use X&Y Arrays in a formula to get and Array answer?

I have a formula L with variables X and Y. X and Y are arrays with eleven numbers in each. I want an array of 121 numbers (11*11) for my answer. But I am only getting eleven answers. (X1,Y1)(X2,Y2)(X3,Y3)......etc. What I want is: (X1,Y1)(X1,Y2)(X1,Y3)......

(X2,Y1)(X2,Y2)(X2,Y3).....etc

Arrays:

x=[15:1:25];

y=[12:1:22];

Formula:

L= sqrt(((x-15).^2)+((y-25).^2))+sqrt(((x-10).^2)+((y-5).^2))+sqrt(((x-40).^2)+((y-10).^2))

Answer:

46.6822 46.2284 45.9273 45.8076 45.9019 46.2441 46.8645 47.7832 49.0065 50.5256 52.3212

How do I set up the arrays X and Y to give me an array answer??

Please help

Answer 1

[Rik]

Use ndgrid to generate the full array of combinations. You could also do it with implicit expansion, but that makes it harder to understand.

[Samuel Flodin]

Using [x,y]= ndgrid (15:1:25,12:1:22);

I am still getting 11 answers:

L =

46.6822 46.2284 45.9273 45.8076 45.9019 46.2441 46.8645 47.7832 49.0065 50.5256 52.3212

[Rik]

That is strange. Both variables should be 11x11 arrays. I haven't noticed any matrix multiplication that would reduce that.

Have you tried splitting the calculations into small steps so you can see where the calculation goes wrong? I'm on mobile so I can't easily test it for you.

[Star Strider]

I am also getting an (11x11) matrix with this code:

[x,y] = ndgrid(15:1:25, 12:1:22);

L = sqrt(((x-15).^2)+((y-25).^2))+sqrt(((x-10).^2)+((y-5).^2))+sqrt(((x-40).^2)+((y-10).^2));

figure
surf(x, y, L)
grid on