fimplicit increasing number of points

I wonder how can I increase the number of points used by the fimplicit command to plot an implicit curve ?

From this question that I asked before I understand that it is possible to get the points used for the plot as a matrix with two lines:

https://www.mathworks.com/matlabcentral/answers/803686-implicit-plane-curve-discretization?s_tid=mlc_ans_email_view#answer_676506

But there seem to be about 500 points (I made more simulations with various curves and the number of points is approximately 500).

My question is: How can I increase that number to get a more precise representation?

I know that I can make changes in the fimplicit.m original matlab file but what is written there is super-professional and I cannot identify where in the code is set the precision.

P.S. My aim is to make a program that computes the perimeter of an implicit curve so for a better precision I need more points.

Answer 1

[Walter Roberson]

fp = fimplicit(@(x,y) x.^2 + 2*y.^2 - 1); %Example
Points1 = [fp.XData;fp.YData];
axis equal
title('mesh default = 151')

fp = fimplicit(@(x,y) x.^2 + 2*y.^2 - 1, 'meshdensity', 255); %Example
Points2 = [fp.XData;fp.YData];
axis equal
title('mesh 255')

size(Points1)

ans = 1×2

2 587

size(Points2)

ans = 1×2

2 1011

[Maxim Bogdan]

That's awesome! From where do you know these stuff? I didn't find this in the documentation of fimplicit...

[Walter Roberson]

It is documented ;-)

https://www.mathworks.com/help/matlab/ref/fimplicit.html#bvds9d6-1-MeshDensity