Change axis of fcontour plot

Hello everyone,

Can someone help me, please?

I'm using this function

fcontour(@(x,y) 3*(x+5)^2 + (x + 5)*(y - 2) + (y - 2)^2);

axis([-100 100 -100 100])

This is the graph

My questions are the following:

1) is it possible to rescale the axis when we use fcontour? (for example in log scale),

2) is it possible to select only a fixed number of contour lines and to visualize only them in the graph?

Thank you very much.

Laura

Answer 1

[Alan Weiss]

The function reference page for fcontour shows at least two ways of choosing the contour lines:

• Use the LevelList name-value argument.
• Use the LevelStep name-value argument.

I think that if you want to scale the data you have several options:

• Set the xyinterval name-value argument to something that works for you.
• Log-scale the data before passing to fcontour.
• Create an axes object before plotting, set the Yscale property to 'log', and then plot into that axes.

Good luck,

Alan Weiss

MATLAB mathematical toolbox documentation

Answer 2

[laura bagnale]

Thank you very much, Alan, this is very helpful!

I already tried with LevelList but now all is more clear!

Best Regards,

Laura