How I can show the values in the contour lines? clabel not work

Question

This is my code:

syms x y;
f= x^2/(y-y^2);
ezcontour(f,[-1,1],[0.1,0.9]);

How can i show the labels? I wan to show something like this: ContourLinesExample

Thank You very much!

What does "clabel not work" mean? – sco1 Aug 11 '16 at 16:17 — sco1, Aug 11 '16 at 16:17

score 1 · Answer 1 · answered Aug 11 '16 at 16:18

1

Using contour :

x = [-1:0.01:1];
y = [0.1:0.01:0.9];
[X, Y] = meshgrid(x,y);
f= X.^2./(Y-Y.^2);
[C, h] = contour(f);
clabel(C, h);

answered Aug 11 '16 at 16:18

Zeta.Investigator

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Owww, really nice and useful answer! Thank you very very much! :) – Motoralfa Aug 11 '16 at 16:24
I guess he meant it doesn't work with *ez*contour. I wonder if there is a way of using only ezcontour since it does not output the C values.... – Zeta.Investigator Aug 11 '16 at 16:28
@Zeta.Investigator Yes, it work very well!, i only have one more question, can i put (0.1 to 0.9) in Y and (-1 to 1) in X? – Motoralfa Aug 11 '16 at 16:30
No, X and Y are the grid matrices. You should put the respective values in **y** and **x** – Zeta.Investigator Aug 11 '16 at 16:31

sco1 · Accepted Answer · 2016-08-11T17:15:14.303

clabel wants as an input the contour matrix being displayed by the Contour object. While ezcontour doesn't return the matrix like contour does, the Contour object has a 'ContourMatrix' property. If you specify an output for ezcontour it will return the handle to the plotted contour that can be queried directly.

For example:

f = @(x, y) x.^2/(y-y.^2);

h = ezcontour(f, [-1, 1], [0.1, 0.9]);
C = h.ContourMatrix;  % R2014b or newer
% C = get(h, 'ContourMatrix');  % R2014a and older
clabel(C, h);

Returns the desired output:

Alternatively, you can can just pass the handle to the contour to obtain the same result:

clabel([], h);

Per the documentation:

If you do not have the contour matrix C, then replace C with [].

How I can show the values in the contour lines? clabel not work

2 Answers2