mesh and surf for surfaces in MATLAB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the mesh function do in MATLAB?

The mesh function creates a wireframe 3D surface plot, showing grid lines without filled faces, which helps visualize the shape of a surface.

beginner

How is surf different from mesh in MATLAB?

surf creates a 3D surface plot with colored, filled faces, making the surface look solid and easier to interpret compared to the wireframe style of mesh.

beginner

What inputs do mesh and surf require?

Both functions typically require matrices X, Y, and Z of the same size, where Z contains the height values and X, Y define the grid coordinates.

beginner

How can you create the grid matrices X and Y for plotting surfaces?

You can use the meshgrid function with vectors for x and y to create matrices X and Y that define the grid points for surface plotting.

beginner

What is a simple example to plot z = sin(sqrt(x^2 + y^2)) using mesh and surf?

Create vectors x and y, use meshgrid to get X and Y, compute Z = sin(sqrt(X.^2 + Y.^2)), then call mesh(X,Y,Z) or surf(X,Y,Z) to plot.

What does the MATLAB mesh function display?

A A bar chart

B A 2D line plot

C A wireframe 3D surface plot

D A filled 3D surface plot

mesh shows a wireframe grid representing the surface shape without filled faces.

Which function shows a colored, filled 3D surface in MATLAB?

A mesh

B surf

C plot

D scatter

surf creates a solid 3D surface with colored faces.

What MATLAB function helps create grid matrices X and Y from vectors?

A meshgrid

B linspace

C plot

D surf

meshgrid converts vectors into coordinate matrices for surface plotting.

If X, Y, and Z are matrices of the same size, which is true?

A They cannot be used for 3D plots

B They must be vectors

C Only <code>Z</code> needs to be a matrix

D They can be used as inputs to <code>mesh</code> or <code>surf</code>

mesh and surf require X, Y, and Z matrices of the same size.

What does the dot operator (e.g., .^2) do in MATLAB surface calculations?

A Element-wise operation on matrices

B Matrix multiplication

C Logical AND

D Transpose

The dot operator applies the operation element-wise, which is needed for surface calculations.

Explain how to create a 3D surface plot using mesh and surf in MATLAB.

Think about how to prepare the grid and height data before plotting.

Describe the visual difference between mesh and surf plots.

Imagine looking at a fishing net versus a solid sheet.