Plotting a multivariable function

6 views (last 30 days)
Katarina Djurovic
Katarina Djurovic on 28 Dec 2020
Answered: Image Analyst on 29 Dec 2020
I want to plot function f(x,y)=1/(x*y), but my code doesn't seem to work
x=[-3,0.1,3];
y=[-3,0.1,3];
[X,Y]=meshgrid(x,y);
Z=1./(X*Y);
surf(X,Y,Z)

Answers (1)

Image Analyst
Image Analyst on 29 Dec 2020
You can do
% Original spacing
x=[-3,0.1,3];
y=[-3,0.1,3];
[X,Y]=meshgrid(x,y);
Z = 1 ./ (X .* Y);
subplot(2, 1, 1);
surf(X,Y,Z);
xlabel('X', 'FontSize', 20);
ylabel('Y', 'FontSize', 20);
zlabel('Z', 'FontSize', 20);
colorbar;
but you are WAY undersampling this function to see the results, which essentially goes to infinity at X and Y both = 0.
% More fine spacing:
subplot(2, 1, 2);
numPoints = 700;
x = linspace(-3, 3, numPoints);
y = linspace(-3, 3, numPoints);
[X, Y] = meshgrid(x,y);
Z = 1 ./ (X .* Y);
surf(X,Y,Z, 'LineStyle', 'none');
xlabel('X', 'FontSize', 20);
ylabel('Y', 'FontSize', 20);
zlabel('Z', 'FontSize', 20);
colormap(jet);
colorbar;
xlim([-.05,.05]);
ylim([-.05,.05]);
zlim([-300, 1200]);
Your sampling at at the top while mine is at the bottom.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!