Why contourf and fcontour gives different images for the same matlab code?

Question

Athira T Das 2023-5-27

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1974529-why-contourf-and-fcontour-gives-different-images-for-the-same-matlab-code

编辑： VBBV 2023-5-29

采纳的回答： VBBV

在 MATLAB Online 中打开

I have code for fcountour as;

syms x y

m =1;

sgm =1;

wo = 0.01;

lambda=532 *10^-9;

k=2*pi/lambda;

Omega = .2;

z=30;

Pho=0.003;

for u=1:length(z)

I=0;

Gamma = ((1i.*k)./(2.*z(u))) + (1./(Pho(u).^2)) + (1./(wo.^2));

Gamma_star = subs(Gamma, 1i, -1i);

alpha = (Gamma_star) - 1./((Gamma.*Pho(u).^4));

C = (1./(4.*(lambda.^2).*(z(u).^4))).*((pi.^2)./(alpha.*Gamma)).*(1./(2.*1i.*sqrt(Gamma)).^m);

fx = ((Omega.^2)./(4.*Gamma)) + ((1i.*k.*x.*Omega)./(2.*z(u).*Gamma)) - ((k.^2.*x.^2)./(4.*z(u).^2.*Gamma));

fy = ((Omega.^2)./(4.*Gamma)) + ((1i.*k.*y.*Omega)./(2.*z(u).*Gamma)) - ((k.^2.*y.^2)./(4.*z(u).^2.*Gamma));

gx = ((Omega.^2)./(4.*Gamma)) - ((1i.*k.*x.*Omega)./(2.*z(u).*Gamma)) - ((k.^2.*x.^2)./(4.*z(u).^2.*Gamma));

gy = ((Omega.^2)./(4.*Gamma)) - ((1i.*k.*y.*Omega)./(2.*z(u).*Gamma)) - ((k.^2.*y.^2)./(4.*z(u).^2.*Gamma));

Bx_p = ((-1i.*k.*x)./(2.*z(u))) + ((1i.*k.*x)./(2.*z(u).*Gamma.*Pho(u).^2)) + (Omega)./(2.*Gamma.*Pho(u).^2) + (Omega./2);

Bx_n = ((-1i.*k.*x)./(2.*z(u))) + ((1i.*k.*x)./(2.*z(u).*Gamma.*Pho(u).^2)) + (Omega)./(2.*Gamma.*Pho(u).^2) - (Omega./2);

By_p = ((-1i.*k.*y)./(2.*z(u))) + ((1i.*k.*y)./(2.*z(u).*Gamma.*Pho(u).^2)) + (Omega)./(2.*Gamma.*Pho(u).^2) + (Omega./2);

By_n = ((-1i.*k.*y)./(2.*z(u))) + ((1i.*k.*y)./(2.*z(u).*Gamma.*Pho(u).^2)) + (Omega)./(2.*Gamma.*Pho(u).^2) - (Omega./2);

Kx_p = ((-1i.*k.*x)./(2.*z(u))) + ((1i.*k.*x)./(2.*z(u).*Gamma.*Pho(u).^2)) - (Omega)./(2.*Gamma.*Pho(u).^2) + (Omega./2);

Kx_n = ((-1i.*k.*x)./(2.*z(u))) + ((1i.*k.*x)./(2.*z(u).*Gamma.*Pho(u).^2)) - (Omega)./(2.*Gamma.*Pho(u).^2) - (Omega./2);

Ky_p = ((-1i.*k.*y)./(2.*z(u))) + ((1i.*k.*y)./(2.*z(u).*Gamma.*Pho(u).^2)) - (Omega)./(2.*Gamma.*Pho(u).^2) + (Omega./2);

Ky_n = ((-1i.*k.*y)./(2.*z(u))) + ((1i.*k.*y)./(2.*z(u).*Gamma.*Pho(u).^2)) - (Omega)./(2.*Gamma.*Pho(u).^2) - (Omega./2);

X = 0;

for l = 0:m

L = (((1i).*sgm).^(m-l)).*nchoosek(m,l);

sum_j = 0;

for j = 0:m

J= (((-1i).*sgm).^(m-j)).*nchoosek(m,j);

sum1 = 0.0;

for p = 0:1/2:l/2

faktor1_P = (((-1).^p).*factorial(l))./(gamma(p+1).*factorial(l-(2.*p))).*(((2.*1i)./(sqrt(Gamma))).^(l-(2.*p))).*exp(fx).*exp(fy);

for s1 = 0:l-2*p

faktor1_s1 = nchoosek((l-(2.*p)),s1).*((1./(Pho(u).^2)).^s1).*((((1i.*k.*x)./(2.*z(u)))+(Omega./2)).^(l-(2.*p)-s1)).*(1./(((2.*1i.*sqrt(alpha))).^(j+s1)));

for q = 0:1/2:(m-l)/2

faktor1_Q = (((-1).^q).*factorial(m-l))./(gamma(q+1).*factorial(m-l-(2.*q))).*(((2.*1i)./(sqrt(Gamma))).^(m-l-(2.*q)));

sum_inner_1 = 0;

for s2 = 0:m-l-2*q

E1 = (exp(((Bx_p).^2)./alpha).*hermiteH(j+s1,((1i.*Bx_p)./(sqrt(alpha)))).*exp(((By_p).^2)./alpha).*hermiteH(m-j+s2,((1i.*By_p)./(sqrt(alpha))))) - (exp(((Bx_n).^2)./alpha).*hermiteH(j+s1,((1i.*Bx_n)./(sqrt(alpha)))).*exp(((By_n).^2)./alpha).*hermiteH(m-j+s2,((1i.*By_n)./(sqrt(alpha)))));

sum_inner_1 = sum_inner_1 + nchoosek((m-l-(2.*q)),s2).*((1./(Pho(u).^2)).^s2).*((((1i.*k.*y)./(2.*z(u)))+(Omega./2)).^(m-l-(2.*q)-s2)).*(1./(((2.*1i.*sqrt(alpha))).^(m-j+s2))).*E1;

end

sum1 = sum1 + faktor1_P.*faktor1_s1.*faktor1_Q.*sum_inner_1;

end

sum_j= sum_j + J.*(sum1);

end

X = X + (L.*sum_j);

end

X = (C.*X);

I = I + abs(vpa(X)) ;

figure;

fcontour(real(I), [-1 1 -1 1]*1E-1, 'Fill','on', 'MeshDensity',150);

colormap('hot');

axis('equal');colorbar('vert');

end

Then i have contourf plot as;

figure;

m =1;

sgm =1;

wo = 0.1;

lambda=532 *10^-9;

k=2*pi/lambda;

Omega = .2;

z=30

z = 30

Pho=0.003

Pho = 0.0030

[x, y] = meshgrid(-1:0.06:1);