How to create a contourf plot from a table?

Question

As far as I understand the way to 3-d plot/ surface plot is "meshgrid". But the data I have has a specific format:

X	Y	Z
1	0.1	10
1	0.2	12
1	0.3	13
2	0.1	11
2	0.2	12
2	0.3	14
3	0.1	11
3	0.2	12
3	0.3	15

The first and second column (X and Y) repeat themselves in that fashion, and I need to plot Z(X,Y).

How Do I do it?

Answer 1

X = 1:1:3 % grid can be set by beginning:step:end
Y = 0.1:0.1:0.3
[x,y] = meshgrid(X,Y); % then make 2d domain 


% z values have to be done manually or can automate if you read your data from txt file
z = [10 12 13; 11 12 14; 11 12 15]; 

% and finally
surf(x,y,z)