Newton-Raphson interpolation with model

Joachim Edberg

2018 11 4

0 个回答

1 次查看（30 天）

0 个投票

Hello! I have a problem with Newton-Raphsons method interpolating with my model Acosh(Bx) + C. I need to find A, B and C using Newton Raphson but i'm just confused with the setup of the matrices. Here's the code:

   Guess = [1,1,1];
 A=Guess(1);
 B=Guess(2);
 C=Guess(3);
 x=1;
 i=1; % counter
 du=1; % to get inside loop
 while abs(du) > 1e-01
 A=Guess(1);
 B=Guess(2);
 C=Guess(3);  
 F1 = A*cosh(B*x) + C;
 F2 = A*cosh(B*x) + C;
 F3 = A*cosh(B*x) + C;
 Fm1 = [F1 F2 F3]';
 J1 = cosh(B*x);                 %d/dA
 J2 = A*x*sinh(B*x);       %d/dB
 J3 = 1;                                  %d/dC
 Jacobi = [J1 J2 J3]';
 du = Jacobi\Fm1;
 Guess = Guess-du;
 i= i+1
 end