Disappear of z coordinate when plotting 3D

Hi,

When I use figure and hold on with a for loop to plot a 3D plot, the z coordinate component always disappears which means the plot becomes 2D. Could anyone help the solve the issue? Thanks in advance. The folloing is the general code.

figure();
for index=1:max_val_1
    other_code_here.....
    for i=1:max_val_2
        other_code_here.....
        plot3(edge(i,1),edge(i,2),edge(i,3), 'o');
        xlabel('x')
        xlim([min max])
        ylabel('y')
        ylim([min max])
        zlabel('z')
        zlim([min max])
    end
    grid on
    hold on
end

Answer 1

[the cyclist]

I think you can "manually" fix this by setting the view. For example, try

view(15,15)

after the plot is made.

I've seen a couple questions like this lately, so I'm wondering if there is some kind of bug with MATLAB defaulting to the "2-D" view (i.e. directly from "above", along the z-axis) when it should not be. I haven't been able to pin it down exactly enough for a bug report, though.

[KD39]

Hi the cyclist,

Thanks for your reply. Also I just discovered that if I move the hold on right after the plot3 statement only the first 'index' loop is plotted. The rest of the for loop 'index' won't be plotted.

This might be MATLAB bug but not sure.

Regards

[the cyclist]

I think you probably want the hold on statement immediately after the figure command (assuming your goal is to show every plot in that figure window). See the documentation for hold for the details.

Answer 2

[Image Analyst]

Since you're plotting only a single point with each call to

plot3(edge(i,1),edge(i,2),edge(i,3), 'o');

you should place "hold on" inside that inner loop. And it should plot all max_val_2 points. Note that there is no reference to "index" inside your "i" loop so you should not expect anything different unless the badly-named "edge" vector changes within the outer "index" loop. By the way, edge(), min(), and max() are the names of a built-in functions so you don't want to use those as the names of your variable.