Why do I keep getting this error? "Error using surf Z must be a matrix, not a scalar or vector."

Moment=zeros(); ki=pi/180; kinc=pi/180; kf=pi; ji=5; jinc=5; jf=100;
for k=ki:kinc:kf
    for j=ji:jinc:jf
        h=sin(k);
        g= cos(k);
        Moment (j/jinc,:) = 1800 + j * h * 39 + j * g * 6;
    end
end
%k is theta j is force
[k,j] = meshgrid(ki:kinc:kf,ji:jinc:jf);
figure
surf(k,j,Moment)

Error using surf
Z must be a matrix, not a scalar or vector.

xlabel('0 (degrees)'); ylabel('Force (lbs)'); zlabel('Moment (lbs-ft)')

[Adam Danz]

Note duplicate

https://www.mathworks.com/matlabcentral/answers/1944824

Answer 1

[the cyclist]

At the risk of stating the obvious, you keep getting that error because Moment is a vector, but it needs to be a matrix.

In your case, it needs to be a 20*180 matrix.

Moment=zeros(); ki=pi/180; kinc=pi/180; kf=pi; ji=5; jinc=5; jf=100;
for k=ki:kinc:kf
    for j=ji:jinc:jf
        h=sin(k);
        g= cos(k);
        Moment (j/jinc,:) = 1800 + j * h * 39 + j * g * 6;
    end
end
%k is theta j is force
[k,j] = meshgrid(ki:kinc:kf,ji:jinc:jf);
size(k)

ans = 1×2

20 180

size(j)

ans = 1×2

20 180

size(Moment)

ans = 1×2

20 1