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cs24451

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注册: 2012-03-15
专业: 光子与光电子器件

[求助] matlab使用自定义函数文件拟合出现错误已有1人参与

代码如下，x,y是想要拟合的曲线对应的x，y值；L1，L2是想要拟合的参数；
下面就是一系列的矩阵计算，通过x求得y
使用ft=fittype('c(x,，L1，L2)');
出现错误：
错误使用 fittype/testCustomModelEvaluation (line 12)
Expression c(x,L1,L2) is not a valid MATLAB expression, has non-scalar coefficients, or cannot be evaluated:
Error in fittype expression ==> c(x,L1,L2)
??? 索引超出矩阵维度。
出错 fittype>iCreateFittype (line 371)
testCustomModelEvaluation( obj );
出错 fittype (line 328)
obj = iCreateFittype( obj, varargin{:} );
原因:
错误使用 fittype/evaluate (line 102)
Error in fittype expression ==> c(x,L1,L2)
??? 索引超出矩阵维度。
怎么解决这个问题？还有其他拟合办法吗？求助好心的坛友~~~~~~~~~~~~~~~~~~~

function [ y ] = c(x,L1，L2)
%UNTITLED2 此处显示有关此函数的摘要
% 此处显示详细说明
m=20; % number of section
n1 = 2.8924; %AlAs
n2 = 3.3702; %GaAS
na=1;
ns=n2;
ra=(na-n2)/(na+n2);
r=(n2-n1)/(n2+n1);
ta=sqrt(1-ra^2);
t=sqrt(1-r^2);
y=zeros(1,2500);
ab1=0;
ab2=0;
for kl=1:2500

beta1 = 2*pi*n1/x(kl)-1i*ab1/2;
beta2 = 2*pi*n2/x(kl)-1i*ab2/2;

T11_a = exp(1i*beta2*L2)/ta;
T12_a = ra*exp(-1i*beta2*L2)/ta;
T21_a = ra*exp(1i*beta2*L2)/ta;
T22_a = exp(-1i*beta2*L2)/ta;
T=[T11_a,T12_a;T21_a,T22_a];

      for k=1:m-1
         T11_n2 = exp(1i*beta1*L1)/t;
         T12_n2 = r*exp(-1i*beta1*L1)/t;
         T21_n2 = r*exp(1i*beta1*L1)/t;
         T22_n2 = exp(-1i*beta1*L1)/t;
         T_n2=[T11_n2,T12_n2;T21_n2,T22_n2];
         T=T*T_n2;

         T11_n1 = exp(1i*beta2*L2)/t;
         T12_n1 = -r*exp(-1i*beta2*L2)/t;
         T21_n1 = -r*exp(1i*beta2*L2)/t;
         T22_n1 = exp(-1i*beta2*L2)/t;
         T_n1=[T11_n1,T12_n1;T21_n1,T22_n1];
         T=T*T_n1;

      end
      T11_n2 = exp(1i*beta1*L1)/t;
      T12_n2 = r*exp(-1i*beta1*L1)/t;
      T21_n2 = r*exp(1i*beta1*L1)/t;
      T22_n2 = exp(-1i*beta1*L1)/t;
      T_n2=[T11_n2,T12_n2;T21_n2,T22_n2];
      T=T*T_n2;

      T_12=[1/t,-r/t;-r/t,1/t]; % from n1 to n2, just cross the interface
      T = T*T_12;

      T11_c = exp(1i*beta2*2*L2);
      T12_c = 0;
      T21_c = 0;
      T22_c = exp(-1i*beta2*2*L2);
      T_c = [T11_c,T12_c;T21_c,T22_c]; % n2 cavity
      T = T*T_c;

      for k=(1:m)
         T11_n2 = exp(1i*beta1*L1)/t;
         T12_n2 = r*exp(-1i*beta1*L1)/t;
         T21_n2 = r*exp(1i*beta1*L1)/t;
         T22_n2 = exp(-1i*beta1*L1)/t;
         T_n2=[T11_n2,T12_n2;T21_n2,T22_n2];
         T=T*T_n2;
         T11_n1 = exp(1i*beta2*L2)/t;
         T12_n1 = -r*exp(-1i*beta2*L2)/t;
         T21_n1 = -r*exp(1i*beta2*L2)/t;
         T22_n1 = exp(-1i*beta2*L2)/t;
         T_n1=[T11_n1,T12_n1;T21_n1,T22_n1];
         T=T*T_n1;
      end


      T11_n2 = exp(1i*beta1*L1)/t;
      T12_n2 = r*exp(-1i*beta1*L1)/t;
      T21_n2 = r*exp(1i*beta1*L1)/t;
      T22_n2 = exp(-1i*beta1*L1)/t;
      T_n2=[T11_n2,T12_n2;T21_n2,T22_n2];
      T=T*T_n2;

      T_12=[1/t,-r/t;-r/t,1/t];
      T = T*T_12;

      T11_c = exp(1i*beta2*9*L2);
      T12_c = 0;
      T21_c = 0;
      T22_c = exp(-1i*beta2*9*L2);
      T_c = [T11_c,T12_c;T21_c,T22_c]; % n2 cavity
      T = T*T_c;

      T11_n2 = exp(1i*beta1*L1)/t;
      T12_n2 = r*exp(-1i*beta1*L1)/t;
      T21_n2 = r*exp(1i*beta1*L1)/t;
      T22_n2 = exp(-1i*beta1*L1)/t;
      T_n2=[T11_n2,T12_n2;T21_n2,T22_n2];
      T=T*T_n2;

      rs1=(n1-ns)/(ns+n1);
      ts1=sqrt(1-rs1^2);
      T11_s = 1/ts1;  % n1 to substrate
      T12_s = rs1/ts1;
      T21_s = rs1/ts1;
      T22_s = 1/ts1;
      T_s = [T11_s,T12_s;T21_s,T22_s];
      T=T*T_s;
      y(kl) = (abs(T(2,1)/T(1,1)))^2;
end

end

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