Phase plane of a differential system

Question

0 个投票

Hi, i'm trying to plot a phase plane but it doesn't work :(

This is the matlab code:

clear all
clc
[X,Y] = meshgrid(0:0.2:5,0:0.2:5);
u = -((3*X)/(2+X))*(Y-X);
v = zeros(26);
figure
quiver(X,Y,u,v);

And matlab answer me: Warning: Matrix is singular to working precision.

Thank you very much for your help !!!

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Answer 1

Star Strider 2015-5-5

0 个投票

You need to do element-wise (array) operations.

Change the ‘u’ assignment to:

u = -((3*X)./(2+X)).*(Y-X);

and it works.

See the documentation on Array vs. Matrix Operations for details on the differences.

Answer 2

abc abc 2015-5-6

0 个投票

thank you very much it works :)

Star Strider 2015-5-6

My pleasure!