Error using mesh z must be a matrix

>> t=linspace(0,2,100);

>> x=t; y=t. ^2; z=t.^3;

>> plot3 (x,y,z), grid

>> t=linspace(–5,5,50); y=x;

>> z=–7./(1+x.^2+y.^2);

>> mesh(z)

[Daniel Pollard]

Well z isn't a matrix, it's a vector, with the same dimensions as t, which is why it gave that error. What were you trying to do?

[Anish Sundar Gowthaman]

@Daniel Pollard What corrections should I make ?

[Daniel Pollard]

I don't know how to answer that when I don't know what the aim of your code is. Star Strider has left an answer - perhaps they figured out what you're after?

Answer 1

[Star Strider]

The arguments to ‘z’ need to be matrices in order for ‘z’ to be a matrix. Use ndgrid or meshgrid (linked to on that page) to create the matrices.

Try this:

t=linspace(0,2,100);
x=t; 
y=t.^2; 
z=t.^3;

figure
plot3(x,y,z)
grid on

t=linspace(-5,5,50); 
y=x;
[X,Y] = ndgrid(x,y);

z= @(x,y) -7./(1+x.^2+y.^2);

figure
mesh(X,Y,z(X,Y))

.