why i am getting the error "Index exceeds the number of array elements (1)" in my code? i am getting the error in line 33.

Question

Atrolita afra 2020-10-16

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/616478-why-i-am-getting-the-error-index-exceeds-the-number-of-array-elements-1-in-my-code-i-am-getting

评论： Adam Danz 2020-10-16

clc
clear variables
close all
segma_N = 10.^-7;
% p_db = 0:5:30; 
% p = 10.^(p_db/10);%power
p = 0.07;
R = 0.5; %Optoelectronic conversion factor 
rng(1);  
I = abs(random('normal',1,2,1,100))*1e-8;
% Processing
%a= 3.99;% Alpha
%b=2; % Beta 
a=[3.99 3.99 3.99 3.5 3.7 3.99]; % Alpha
b=[6 4 2 2 2 2]; % Beta
% nz = zeros(1, length(p_db));
% z = zeros(1, length(p_db));
SNR = 0:2:30;
SNR_db = 10.^(SNR/10);
nz = zeros(1, length(SNR_db));
z = zeros(1, length(SNR_db));
 
 for k=1:length(a)
    for j = 1:length(z)  
    
     yz =log2(1+((p(j).*R.*I)./segma_N).^2).*zpdf(I,a(k),b(k));
     z(k,j) = trapz(I, yz);   
    
    end
end
      
% Plot
figure
semilogy(SNR_db,nz(1,:),'-ks','MarkerFaceColor','k')
hold on
semilogy(SNR_db,nz(2,:),'-ro','MarkerFaceColor','r')
semilogy(SNR_db,nz(3,:),'-b^','MarkerFaceColor','b')
grid on
xlabel('SNR [dB]')
ylabel('channel Cpacity')
title('Intial Results')
xlim([0 30])

and the function zpdf is

function G = zpdf(I,a,b)
% a: Alpha
% b: Beta
c = 0.2;   %Gamma
%d = 2.6124; %0.8;   %Big omega prime
omega = 1.3265;
b_0 = 0.1079; %Average power of the coupled-to-LOS scattering component
row = 0.55;  %Scattering power coupled to the LOS component
d = (omega+row.*2.*b_0+2.*sqrt(2.*b_0.*omega.*row));%Big omega prime Average optical power of coherent contributions
Aperture_radius = 0.1;   %Aperture_radius
segma_s = 0.2;           %Jitter standard deviation
omega_z =  2.5;          %Beam Width
  
v = (sqrt(pi)*Aperture_radius)/(sqrt(2)*omega_z);
omega_zeq_2 = (omega_z^2)*(sqrt(pi)*erf(v))/(2*v*exp(-(v^2))); 
g = omega_zeq_2/(2*segma_s);
A0 = (erf(v))^2;
A = (2*(a^(a/2))/((c^(1+a/2))*gamma(a)))*(((c*b)/(c*b+d))^(b+a/2));
First = (((g^2)*A)/2)*(I.^-1);
count1 = 0;
for k = 1:b
    
    ak = (nchoosek(b-1,k-1))*(((c*b+d)^(1-k/2))/gamma(k))*((d/c)^(k-1))*((a/b)^(k/2));
    
    Part1 = ak*(a*b/(c*b+d))^(-(a+k)/2);
     
    Part2_1 = (a*b/(c*b+d));
    Part2_2 = I/A0;
    
    Part2 = meijerG([],g^2,[g^2,a,k],[],Part2_1*Part2_2);
    count1 = count1 + Part1.*Part2;
end
G = First.*count1;
end

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Atrolita afra 2020-10-16

yz =log2(1+((p(j).*R.*I)./segma_N).^2).*zpdf(I,a(k),b(k));

i am getting the error in this line saying , "Index exceeds the number of array elements (1)."

Atrolita afra 2020-10-16

-_- then what is the solution?

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Answer 1

Adam Danz 2020-10-16

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/616478-why-i-am-getting-the-error-index-exceeds-the-number-of-array-elements-1-in-my-code-i-am-getting#answer_516153

在 MATLAB Online 中打开

From you code,

p = 0.07;

p has 1 value, size (1,1).

In the loop below, when j>1 you're getting the indexing error because p only has 1 value.

 for k=1:length(a)
    for j = 1:length(z)  
    
     yz =log2(1+((p(j).*R.*I)./segma_N).^2).*zpdf(I,a(k),b(k));
     %            ^^^
     z(k,j) = trapz(I, yz);   
    
    end
end

There may be other errors but I'm not going to read through the code to figure that out. If there are more errors, please attach ther data so I can run the code.