Output argument 'V_cv' is not assigned on some execution paths.

i'm having this error in matlab function block, referred to the code below: some previously topic help me in check every IF-ELSEIF-ELSE paths and i think V_cv is defined for every cicle. what can be the mistake? I Can't do debugging 'cause the error stops simulink in the calling of this function

COMPLETE ERROR MESSAGE: Output argument 'V_cv' is not assigned on some execution paths.

Function 'MATLAB Function2' (#24.10.14), line 1, column 11:

"V_cv"

Launch diagnostic report.

function [V_cv, ga1, ga2, ga3, gb1, gb2, gb3, gc1, gc2, gc3]   = fcn(SOCA, SOCB, SOCC)
V_Ilim=0.8;
persistent R
R=[];
if isempty(R)==1
    R=0;
end

if R==0
    V_cv=0;

        ga1=[0 0 0 0];
        ga2=[0 0 0 0];
        ga3=[0 0 0 0];
        
        gb1=[0 0 0 0];
        gb2=[0 0 0 0];
        gb3=[0 0 0 0];
        
        gc1=[0 0 0 0];
        gc2=[0 0 0 0];
        gc3=[0 0 0 0];
end
%% CV
%condition 1
if all(SOCA>=V_Ilim) 
   R=1;  
   V_cv=Vocp_function(SOCA(1));
end
%condition 2
if all(SOCB>=V_Ilim)
   R=2; 
   V_cv=0;
end
%condition 3
if all(SOCC>=V_Ilim)
   R=3;  
   V_cv=0;
end

if R==1
    if SOCB(1)<=V_Ilim || SOCC(1)<=V_Ilim
        V_cv=Vocp_function(SOCA(1));
   
        ga1=[1 0 0 1];
        ga2=[1 0 1 0];
        ga3=[1 0 1 0];
        
        gb1=[1 0 0 1];
        gb2=[1 0 1 0];
        gb3=[1 0 1 0];
        
        gc1=[1 0 0 1];
        gc2=[1 0 1 0];
        gc3=[1 0 1 0];
        
    elseif SOCB(2)<=V_Ilim || SOCC(2)<=V_Ilim
        V_cv=Vocp_function(SOCA(1));
        ga1=[1 0 1 0];
        ga2=[1 0 0 1];
        ga3=[1 0 1 0];
        
        gb1=[1 0 1 0];
        gb2=[1 0 0 1];
        gb3=[1 0 1 0];
        
        gc1=[1 0 1 0];
        gc2=[1 0 0 1];
        gc3=[1 0 1 0];
        
    elseif SOCB(2)<=V_Ilim || SOCC(2)<=V_Ilim
        V_cv=Vocp_function(SOCA(1));
        ga1=[1 0 1 0];
        ga2=[1 0 1 0];
        ga3=[1 0 0 1];
        
        gb1=[1 0 1 0];
        gb2=[1 0 1 0];
        gb3=[1 0 0 1];
        
        gc1=[1 0 1 0];
        gc2=[1 0 1 0];
        gc3=[1 0 0 1];
    else
        V_cv=0;
    end
        
end
end

[Walter Roberson]

persistent R
R=[];
if isempty(R)==1
    R=0;
end

What is the purpose of doing the R=[] followed by isempty(R ) ? Why not just directly do

R = 0;

??

What is the purpose of using persistent when you always overwrite R ?

[Federico Lusardi]

Thank you Walter, in fact it is a reduntant (and usless) part of code. it was only a first attempt to be sure that in all condition V_cv is assigned and defined, to avoid the error.

Answer 1

[Gargi Patil]

In the given function, an error is being thrown due to the output variable ‘V_cv’. The error message ‘Output argument is not assigned on some execution paths’ typically occurs if there is an if-else pathway for which the output variable is not assigned a value. To fix this, a catch-all ‘else’ condition should be used that assigns a default value to the variable ‘V_cv’ when none of the ‘if’ conditions are meant.

You can refer to the following question link which also explains this error:

https://www.mathworks.com/matlabcentral/answers/335451-output-argument-t-is-not-assigned-on-some-execution-paths

[Federico Lusardi]

Thank you Gargy, in fact the problem was that for path If R==2 and R==3 no V_cv was define. By adding and checking else condition I solve the problem.