How to plot coupling functions?
1 view (last 30 days)
Show older comments
Want to plot these coupling functions r(t) and p(t) (in image) on a graph. I tried using this code and ended up with a blank graph(without errors) . Kindly help. Please note t varies as 2 to 3 with stepping of 0.01 .
z1 = -1.0629;
z2 = 0.5948;
%Code for r(t)
r_int1 = @(s) (2/3 - s).^(-1/2) .* (6 + abs(r(s))+abs(p(s))) ./ (5.*exp(s+4).*(1+abs(r(s))+abs(p(s))));
r_int2 = @(s) (t-s).^(-1/2) .* (6+abs(r(s))+abs(p(s))) ./ (5*exp(s+4).*(1+abs(r(s))+abs(p(s))));
r = @(t) ( z1.*t.^(-1/3)/gamma(1/2) .* integral(r_int1, 0, 2/3) ) + ( (1/gamma(1/2)) .* integral(r_int2, 0, t) );
%Code for p(t)
p_int1 = @(s) (3/2 - s).^(-4/5) .* (1/exp(2*s)) .* (sin(r(s))+sin(p(s)));
p_int2 = @(s) (t - s).^(-4/5) .* (1/exp(2*s)) .* (sin(r(s))+sin(p(s)));
p = @(t) ( z2.*t.^(-3/2)/gamma(1/5) .* integral(p_int1, 0, 3/2) ) + ( (1/gamma(1/5)) .* integral(p_int2, 0, t) );
fp = fplot(r,p,[2 3]);
fp.Marker = '*';
2 Comments
Answers (1)
Cris LaPierre
on 8 Jun 2021
If I don't use fplot, I do get a more descriptive error message. Based on the code you have shared, you are using your function handle r in you computation of r_int1 and r_int2 before it has been defined.
z1 = -1.0629;
z2 = 0.5948;
%Code for r(t)
r_int1 = @(s) (2/3 - s).^(-1/2) .* (6 + abs(r(s))+abs(p(s))) ./ (5.*exp(s+4).*(1+abs(r(s))+abs(p(s))));
r_int2 = @(s) (t-s).^(-1/2) .* (6+abs(r(s))+abs(p(s))) ./ (5*exp(s+4).*(1+abs(r(s))+abs(p(s))));
r = @(t) ( z1.*t.^(-1/3)/gamma(1/2) .* integral(r_int1, 0, 2/3) ) + ( (1/gamma(1/2)) .* integral(r_int2, 0, t) );
%Code for p(t)
p_int1 = @(s) (3/2 - s).^(-4/5) .* (1/exp(2*s)) .* (sin(r(s))+sin(p(s)));
p_int2 = @(s) (t - s).^(-4/5) .* (1/exp(2*s)) .* (sin(r(s))+sin(p(s)));
p = @(t) ( z2.*t.^(-3/2)/gamma(1/5) .* integral(p_int1, 0, 3/2) ) + ( (1/gamma(1/5)) .* integral(p_int2, 0, t) );
% fp = fplot(r,p,[2 3]);
% fp.Marker = '*';
plot(r(2:.01:3),p(2:0.01:3))
6 Comments
Cris LaPierre
on 9 Jun 2021
I'm not sure I've seen recursive integration before. Perhaps someone else can provide insight on that.
See Also
Categories
Find more on Gamma Functions in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!