Plotting 3D functions

Given: Create both a contour and surface plot for the following function.

Find:

• Create an x vector between -2 and 2, with a step size of .2
• Create a y vector between -2 and 2, with a step size of .2
• Create a matrix X and Y that contains a grid of coordinate pairs from x and y
• Create a matrix Z that is the same size as X and Y

Create the following plots, with labels

• Contour plot
• Surface plot

Issue: I have what I believe to be the correct code, however, it's giving me an error stating not enough input arguments...

My Solution: What am I missing here?

x=-2:0.2:2
y=x
[X,Y]=meshgrid(x,y)
Z=x.*exp.^-(x.^2+y.^2)
contour(X,Y,Z)
surf(X,Y,Z)

Answer 1

[the cyclist]

You used exp as if it were a constant (e) that is raised to a power. Instead, you should have used it as a function.

You also used x and y instead of X and Y, when calculating Z.

x=-2:0.2:2;
y=x;
[X,Y]=meshgrid(x,y);
Z=X.*exp(-(X.^2+Y.^2));

figure
contour(X,Y,Z)

figure
surf(X,Y,Z)

[Spaceman]

Eureka! I figured it out after the fact, still new to this whole realm. I am very thankful we live in an age of information such that if I can't understand something after trying it 9 different ways, someone can show me the correct, 10th way. Thank you.

Also do we need parentheses around (X.^2+Y.^2)? As it works just to same without. I only ask because I would put them, but I feel I abuse them.

One last weird question, why when we use a semicolon after a figure, plot, etc... Does it still pop up/display? A semicolon supresses everything I thought.

[the cyclist]

If you don't use parentheses, you are relying on the defined operator precedence. Sometimes, parentheses are better, just for clarity.

Semicolons suppress command window output, not all output. A semicolon such as

surf(X,Y,Z);

is superfluous.

[Spaceman]

Thank you for taking the time to clear that up!