The meshgrid() Function in MATLAB

This tutorial will discuss creating a grid using the meshgrid() function in Matlab.

Create a Grid Using the meshgrid() Function in MATLAB

To create 2D and 3D grids in Matlab, we can use Matlab’s built-in function meshgrid(). In Matlab, grids are used to plot data on a 3D plane. To plot a vector or matrix on a 3D plane, we have to create a 2D or 3D grid using the meshgrid() function. In 2D plots, we pass the x and y coordinates as a vector, but in 3D, we have to pass a matrix instead of a vector. We can use the meshgrid() function to convert vectors into matrices which will be used to plot the data in a 3D plane. For example, let’s convert two vectors containing x and y coordinates to matrices using the meshgrid() function. See the code below.

x = 1:4
y = 1:6
[X,Y] = meshgrid(x,y)

Output:

x =

     1     2     3     4


y =

     1     2     3     4     5     6


X =

     1     2     3     4
     1     2     3     4
     1     2     3     4
     1     2     3     4
     1     2     3     4
     1     2     3     4


Y =

     1     1     1     1
     2     2     2     2
     3     3     3     3
     4     4     4     4
     5     5     5     5
     6     6     6     6

In the output, we can see the difference between the small x and y and capital X and Y. We cannot use the small x and y coordinates to plot data in a 3D plane, but we can use the capital X and Y coordinates to plot the data in a 3D plane. For example, let’s create a vector to plot on a 3D plane using the X and Y coordinates and the surf() function. See the code below.

x = 1:4;
y = 1:6;
[X,Y] = meshgrid(x,y);
Z = X.^2 + Y.^2;
surf(X,Y,Z)

Output:

The surf() function is used to plot the matrix Z on a 3D plane. The matrix Z should have the same size as the X and Y matrices. We can also create a 3D grid using three or one input vector and three output variables using the meshgrid() function. The meshgrid() function will create a 3D grid that forms a cube of grid points. If we pass only one input vector in the meshgrid() function, the function will take the other two coordinates from the indices of the first vector.