MyFunction Call generates Error

I am facing some problems in executing my code main.m which calls a function called Myfunction.m,I hope someone can help me to resolve that problem :

clc;
clear all;
close all ;

dim1=5;
dim2=3;

Freq=3e9;
Gr=20;         % Receive Antenna Gain
Gt=2;          % Transmit Antenna Gain
P_T=0.001;  %watt (Transmit Power) 
PathLossExponent=2;
std=2;



ReaderLoc = [dim1/3 dim2/3; dim1/3 2*dim2/3; 
        2*dim1/3 dim2/3; 2*dim1/3 2*dim2/3]; 
mobileLoc  = dim1*rand(1,2);

for m = 1:3
                distanceB(m) = sqrt( (mobileLoc(:,1)-ReaderLoc(m,1)).^2 + (mobileLoc(:,2)-ReaderLoc(m,2)).^2  );
                [PrMob,Pr0,Dref] = Myfunction(P_T, Gt, Gr, Freq, PathLossExponent,distanceB(m),std);
                PrMobNode(m) = PrMob;
               
end


%the above main code should get a return value calculated by Myfunction.m%%
%%%%%Myfunction.m%%%%% looks like :

C=physconst('Lightspeed')

function [Pr,Pr0,Dref] = Myfunction(PTx , TXAntennaGain, RXAntennaGain, Freq, PathLossExponent,DistanceMsr,std) 
    
    Dref=0.5;
    PTxd = 10*(log10(PTx));
    Wavelength = C/Freq;
    M = Wavelength/(4*pi*Dref);
    
    
    Pr0= PTxd +2*TXAntennaGain +2*RXAntennaGain - 40*log10(1/M);
    GaussRandom=normrnd(0,std);
    
    Pr= Pr0 - (20*PathLossExponent* log10(DistanceMsr/Dref)) + GaussRandom;
    
    
   
end




%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

The errors generated are:
1) when executing the function code:

Error: File: Myfunction.m Line: 3 Column: 26
Function with duplicate name "Myfunction" cannot be defined.

2)when executing the main.m

Error: File: Myfunction.m Line: 3 Column: 26
Function with duplicate name "Myfunction" cannot be defined.

Error in main (line 24)
                [PrMob,Pr0,Dref] = Myfunction(P_T, Gt, Gr, Freq, PathLossExponent,distanceB(m),std);
 

Answer 1

[Stephen23]

The problem is that you think that you wrote a function, but you actually wrote a script:

https://www.mathworks.com/help/matlab/matlab_prog/scripts-and-functions.html

These are the first three lines of your script:

C=physconst('Lightspeed') % <------ this line makes it a script!

function [Pr,Pr0,Dref] = Myfunction(...)

A function must not have any code outside of any function definitions. Your C=... line is how you told MATLAB that you want a script, not a function, because it is not inside a function definition. That means that your script (known to MATLAB by its filename) includes a local function which has the same name as the script itself: Ouch! That is why it throws an error.

The solution is simple: get rid of all code that are not inside the main or local function definitions.

[Adam Danz]

@ ilyass ilyass, check out the link below for an example of a function and an example of a script that contains a function. Only comments can come before a function declaration unless you're writing a script.

https://www.mathworks.com/help/matlab/ref/function.html

Answer 2

[ilyass ilyass]

Thank you Stephen & Adam for your indications,I realised that the working directory was not the same where the files were located so a simple command : cd ThatDiretory on the command window would solve the problem.