How to find argument value?

Hi, I have a, b vectors and rectangular grid made of them, I write a function and obtain function values on grid. How can I find which values of 'a' and 'b' vectors correspond to particuar function value? Here's the code...

a= [1,2]
b=[3,4]
[m,n]=ndgrid(a,b)
x=[m(:),n(:)]
u = @(a, b)(a.^2+b)
g=(u(x(:,1),x(:,2)).')

Code gives me g=4,7,5,8 values.... I want to know for example which values of 'a' and 'b' created g=7 value. Thanks.

Answer 1

[madhan ravi]

mng  = [m(:), n(:), g(:)];

ab_at_g = mng(ismember(mng(:,3),7),1:2)

[Ani Asoyan]

It says : Dimensions of matrices being concatenated are not consistent.

[madhan ravi]

Check once more, however j don’t see the point why you use ndgrid(...) here.

[Ani Asoyan]

It worked ! As always, Thank you so much !!

[Ani Asoyan]

I created that to obtain matrix, is there an easier way/?

[madhan ravi]

It would give you the same result without ndgrid(...) ;)

[Ani Asoyan]

I didn't know that, but I'll learn more about it, thank you once again !!