Matrix to Surf Incorrect

Hello, I have a 4x3 matrix. When I use the surf function, it does not plot properly. I want:

• X Axis = 1st Column
• Y Axis = 2nd Column
• Z Axis = 3rd Column

Attached is a screenshot of the code and what shows up.

Thank you!

Answer 1

[Swetha Polemoni]

Hi,

As per my understanding you want these following points to be plotted.

(x,y,z)=> (15,50,0.1576549),(25,20,0.1581748),(25,50,0.157905),(25,80,0.157428).

• Understanding the working of "surf".

For a given matrix A, surf(A) will plot A(i,j) at i on x-axis and j on y axis where i and j are row and column number respectively.

Consider the following example for better understanding

Let A=[a,b;c,d]

surf(A) will surface plot the element b of matrix A at (1,1) as x and y coordinates.

X=[15 50 0.1576549; 25 20 0.1581748; 25 50 0.157905; 25 80 0.157428 ]

According to the above explanation, surf(X) will surface plot

the following points (1,1,15),(2,1,25),(1,2,50) etc. As per my understanding, surf will not work for your application.

• Undersatnding the working of "plot3"

(x,y,z)=> (15,50,0.1576549),(25,20,0.1581748),(25,50,0.157905),(25,80,0.157428)

For plotting these points "plot3" can be used.

Following code snippet is for better understanding.

X=[15 50 0.1576549; 25 20 0.1581748; 25 50 0.157905; 25 80 0.157428 ]      
plot3(X(:,1),X(:,2),X(:,3))