Gap in MATLAB surface plot-CodePudding

I'm trying to plot a cone in MATLAB using the following code. However, when MATLAB generates the plot, there is a gap in the surface as shown in the image below. Would anyone be able to suggest a way to close it?

clearvars; close all; clc;

[theta, r] = meshgrid(-pi:0.1:pi, -4:0.1:6);
x = (r-1).*cos(theta);
y = (r-1).*sin(theta);
z = r;

% 3-D plot
figure
surf(x, y, z);
xlabel("x"); ylabel("y"); zlabel("z");
zlim([0 8]);
axis square

CodePudding user response：

The problem is that the list of theta stops before reaching pi because the increments of 0.1 do not reach the upper bound.

For example, you may use the line

[theta, r] = meshgrid(-pi:(2*pi/20):pi, -4:0.1:6);

to complete the circle in 20 steps.