can anyone check this code?

function l=LCR_CF(k,c,sigma)

%% pdf of process of various values of system parameters

for x=0:.0625:10
    temp=0;
    LCR=0;
    
    ro=(x.^2/sigma);
    ro=20*log10(ro);
    for p=0:10
        for n=0:p+1
            
            
            %    closed term expansion
            b=nchoosek(p+(1/2),n);
            
            % gamma term calculation
            f=factorial(p);
            g=(gamma(p+1))*(gamma(c));
            g_ma=((ro.^(p+0.5))*(k.^c)*(2*sqrt(2*pi)))/(g*f);
            
            % bessel function term calculation
            z=2*sqrt(k*(1+ro));
            K = besselk(p-n+c,z);
            
            % Exponential term calculation
            exponential=exp(-ro);
            % Last term
            q=(p-n+c)/2;
            last_term=((k/(1+ro)).^q);
            
            % Final pdf function
            
            temp1= b*g_ma*K*exponential*last_term;
            temp=temp+temp1;
        end
        LCR=LCR+temp;
    end
    
    l(1,x/(.0625)+1)=LCR;
end

THIS IS THE FUNCTION I AM TRYING TO PLOT BUT I AM GATTING AN ERROR ,""Undefined function 'LCR_CF' for input arguments of type 'double'.""

HOW CAN I SOLVE THIS?

I HAVE CALLED THIS FUNCTION BY THE FOLLOWING CODE:

clc
clear all
close all

syms x ;

%% For different values of k and c. Change the value of k and c according to figure.
sig=1;

y1=LCR_CF(0.2,1.5,sig); % Put the values of k,c,sig accordingly
y2=LCR_CF(0.5,1.5,sig);
y3=LCR_CF(1,1.5,sig);
y4=LCR_CF(1.5,1.5,sig);

y5=LCR_CF(.2,2,sig);
y6=LCR_CF(.5,2,sig);
y7=LCR_CF(1,2,sig);
y8=LCR_CF(1.5,2,sig);

%% Ploting data
x=0:0.0625:10;
figure
% plot(y1,x,'b',y2,x,'b',y3,x,'b',y4,x,'b',y5,x,'g--',...
%     y6,x,'g--',y7,x,'g--',y8,x,'g--');
plot(x,y1,'b',x,y2,'b',x,y3,'b',x,y4,'b',x,y5,'g--',...
    x,y6,'g--',x,y7,'g--',x,y8,'g--');

xlim([0 10]);
ylim([0 1]);

title('Normalized LCR');
xlabel('x');
ylabel('N(x)');
txt = {'Sigma=1','C=1.5, Solid Line', 'C=2, Dotted Line'};
text(6,6,txt);

txt = {'k=1.5'};
text(1,6,txt);

[David Hill]

If you want us to check it you should at least put your code in a code block with proper indenting.

[Atrolita afra]

OK, MY MISTAKE

[Ameer Hamza]

We don't know the purpose of your code, whether the issue is related to an error or you think that some part of the code can be optimized. See this: https://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Atrolita afra]

i was trying to plot an equation

[Atrolita afra]

The error message is given below:

Undefined function 'LCR_CF' for input arguments of type 'double'.

Error in LCR_main (line 10)

y1=LCR_CF(0.2,1.5,sig); % Put the values of k,c,sig accordingly

[Ameer Hamza]

Amrin, where have you placed the file LCR_CF.m file which contains your function code?

[Atrolita afra]

in the same folder why i have placed the file LCR_main.m

[Atrolita afra]

Sorry , it was on the different folder and after solving this i have got another error:

Error using  + 
Matrix dimensions must agree.

Error in LCR_CF (line 37)
        temp=temp+temp1;

Error in LCR_main (line 10)
y1=LCR_CF(0.2,1.5,sig); % Put the values of k,c,sig accordingly
 

[Ameer Hamza]

yes, I could see the error in your function LCR_main. Can you describe what are you trying to do in that function. Are you implementing some equations?

[Atrolita afra]

yes i was trying to plot an equation

[Ameer Hamza]

Can you attach the equation?

[Atrolita afra]

[Atrolita afra]

instead of infinity i was trying with 10

Answer 1

[Ameer Hamza]

I have corrected the syntax issue in your code. The MATLAB function nchoosek does not work for fractional numbers. However, Now it gives infinity at 0 and also gives complex values. I am not sure whether this is correct or wrong.

function l=LCR_CF(k,c,sigma)

%% pdf of process of various values of system parameters

nck = @(n, k) gamma(n+1)./(gamma(k+1).*gamma(n-k+1));

X = 0:.0625:10;
l = zeros(size(X));
for i=1:numel(X)
    x = X(i);
    temp=0;
    LCR=0;
    
    ro=(x.^2/sigma);
    ro=20*log10(ro);
    for p=0:10
        for n=0:p+1
            %    closed term expansion
            b=nck(p+(1/2),n);
            
            % gamma term calculation
            f=factorial(p);
            g=(gamma(p+1))*(gamma(c));
            g_ma=((ro.^(p+0.5))*(k.^c)*(2*sqrt(2*pi)))/(g*f);
            
            % bessel function term calculation
            z=2*sqrt(k*(1+ro));
            K = besselk(p-n+c,z);
            
            % Exponential term calculation
            exponential=exp(-ro);
            % Last term
            q=(p-n+c)/2;
            last_term=((k/(1+ro)).^q);
            
            % Final pdf function
            
            temp1= b*g_ma*K*exponential*last_term;
            temp=temp+temp1;
        end
        LCR=LCR+temp;
    end
    
    l(i)=LCR;
end

[Atrolita afra]

But already i have solved an equation using nchoosek.

[Atrolita afra]

Oh i got your logic thanks for the infornation. though i don't know wheather it is the correct figure or not but i got that i will manage the rest !

[Ameer Hamza]

Glad to be of help. Best of luck for your project.