What type of 3d chart do you want to create?
For a surface, you could use the following syntax (Z needs to be a matrix). Just note that the rows correspond to y and the columns to x, so you need to transpose the matrix to get what you want.
surf(Z) creates a surface plot and uses the column and row indices of the elements in Z as the x- and y-coordinates.
Z = rand(10,20);
surf(Z') %
xlabel('X')
ylabel('Y')
zlabel('Z')
This syntax is not universal across all 3D plotting functions. When it isn't, you can create X and Y vectors first.
x = 1:size(Z,1);
y = 1:size(Z,2);
[X,Y] = meshgrid(x,y);
scatter3(X,Y,Z')
