Explanation of surf plot

I used the following code to plot some example data:

A(1,1:51)=0:1:50;
A(2,2:51)=1;
A(3,2:51)=2;
A(4,2:51)=3;
A(5,2:51)=4;
A(6,2:51)=5;
A(7,2:51)=6;
A(8,2:51)=7;
A(9,2:51)=8;
A(10,2:51)=9;
A(1:10,1)=[0 1 2 3 4 5 6 7 8 9];

f=A(1,2:51);
t=A(2:10,1);
d=(A(2:end,2:end))';

surf(t,f,d,'EdgeColor','none');
view(0,90)
xlim([0 10])

colorbar

I'd like to understand how I get the code to plot all of the data.

There are nine different values in matrix 'A', but only 1-8 are plotted. Why is that?

Thanks!

[Dyuman Joshi]

"Why is that?"

Take a look at your code. Look at how the variables used as input to surf have been defined.

[Louise Wilson]

Sorry, but this doesn't help me... I can see how the variables are defined, but don't understand what is wrong about it.

[Louise Wilson]

• where x = 1, c = 1, which is what I desire - but for some reason, the final x data point (9) isn't plotted. I'd like to understand why that is, so I can remedy it.

Answer 1

[Cris LaPierre]

What if we simplify the code?

X = 0:9;
Y = 0:50;
A = ones(51,10) .* X;

surf(X,Y,A,'EdgeColor','none');
colorbar

surf colors the face between points. So if you have 10 point along x, there are 9 faces (0-1, 1-2, ..., 8-9).

[Joel Hottinger]

I think the key here is the between the points line. This becomes very apparent if we have a 2x2 matrix:

a = [1,1;2,2];
surf(a)
view(2)

[Louise Wilson]

Yup, I see now, thanks!