Matlab drawing points and show values

问题

I have a simple plot question.

On x axis, the values are K, say from 2 to 12, discrete. On y axis, the values are C, say from 1 to 10, discrete.

My function is piecewise:

K if K<2C; K+2C if K>=2C;

I want to show the values at points (K,C):

(1,1) Show as 1 (1,2) Show as 1 (2,1) Show as 4 (2,2) Show as 2 ect.

How would I do that?

Many thanks,

Casper

回答1:

You can use ndgrid to create K and C:

[K C] = ndgrid(2:12,1:10);

then use logical indexing to calculate the separate parts:

z=zeros(11,10);
ind = K>=(2*C);
z(~ind) = K(~ind);
z(ind) = K(ind)+2*C(ind);

then plot any way you want:

surf(C,K,z);

or

image(z);

and others....

来源：https://stackoverflow.com/questions/19062382/matlab-drawing-points-and-show-values