If statement for 2 different variables.

I have an equation:

x = [10 / pi + j / sin(i-1)] * cos[j * (i-1) * pi]

where i = 2 to 6 and j = 1 to 7. I am trying to make a code with both i and j. I am solving this equation for all combinations. For example, I want to solve the equation when i = 2 and j = 1, 2, ..., 7. And when i = 3, j = 1, 2, ..., 7. The end result should also be put in a matrix i by j = 5 by 7.

Thank you to all that reply!

[Dyuman Joshi]

Look into the 1st example provided in the documentation of for loop

[Kavi Patel]

How did I not see this, thank you so much!

[Star Strider]

A loop is actually not necessary. See my Answer.

Answer 1

[Star Strider]

Try this —

x = @(i,j) (10 / pi + j ./ sin(i-1)) .* cos(j .* (i-1) * pi);

i = 2:6;
j = 1:7;
[I,J] = ndgrid(i,j);
Iv = I(:);
Jv = J(:);
Xv = x(Iv,Jv);

X = x(I,J)                                  % Matrix

X = 5×7

-4.3715 5.5599 -6.7483 7.9367 -9.1251 10.3135 -11.5019 4.2828 5.3826 6.4823 7.5821 8.6818 9.7816 10.8814 -10.2693 17.3554 -24.4416 31.5278 -38.6139 45.7001 -52.7863 1.8618 0.5404 -0.7809 -2.1023 -3.4236 -4.7450 -6.0663 -2.1403 1.0974 -0.0546 -0.9882 2.0311 -3.0739 4.1167

figure
surf(I,J,X)                                 % Surface Plot
grid on
colormap(turbo)
xlabel('i')
ylabel('j')
zlabel('x(i,j)')

ResultVectors = table(Iv,Jv,Xv)                 % Table Of Vectors

ResultVectors = 35×3 table
    Iv    Jv       Xv    
    __    __    _________

    2     1       -4.3715
    3     1        4.2828
    4     1       -10.269
    5     1        1.8618
    6     1       -2.1403
    2     2        5.5599
    3     2        5.3826
    4     2        17.355
    5     2        0.5404
    6     2        1.0974
    2     3       -6.7483
    3     3        6.4823
    4     3       -24.442
    5     3      -0.78095
    6     3     -0.054593
    2     4        7.9367

.