tg.m

迭代实现非线性函数（电离层延迟模型）的参数拟合问题

clear;
t=linspace(10,86400,24);
fm=linspace(0,50,10);
 ff=[2 1.5 1 0.8 0.85 1 2.1 3.6 4.2 5 5.2 5.5 5.6 5.5 5.3 5.2 4.2 4 3 2.2 1.6 1.4 1.3 2];
A1=1;
B=0.00000000100;
C=1007947671;
D=40000;
alpha0=50;
alpha1=5;
alpha2=0.5;
alpha3=1.5;
  
beta0=5000;
beta1=1000;
beta2=10;
beta3=4;

gama0=1;
gama1=-5.5;
gama2=-0.08;
gama3=-0.002073072;
for k=1:10;
fm(k)=40
    A=a2(alpha0,alpha1,alpha2,alpha3,fm(k));
A4=a4(beta0,beta1,beta2,beta3,fm(k));
A3=a3(gama0,gama1,gama2,gama3,fm(k));
x=2*pi*(t-A3)/A4;

for i=1:24
     Tg(1,i)=A1+A*(1-x(i).^2/2+x(i).^4/24)+B*((t(i)-A3)^2-C);
if (abs(x(1,i))>=1.57)
    Tg(1,i)= A1+B*((t(i)-A3)^2-C);

end 

end

plot(t,Tg,'r',t,ff,'g')
hold on
end



grid on;