why can't use functions, although I know the inputs and outputs are there?

hi, I have a large GUI and in order to save time I am using functions. but only in one function that I input negative and positive integers, generates this following error:

 Output argument "sentido" (and maybe others) not assigned during call to

I know that normally this occurs when there are loop errors which doesn't define the output values or there is not enough inputs. but you see, I have checked over and over but I can't find these. also sometimes, it functions.

may be this cucurs because I'm using serial port data for input data of the function. here is the code of the function:

function [sentido] = giro(x,INPUTejeX)
inputejeX=regexp(INPUTejeX, '(+|-)?\d+(\.\d+)?', 'match', 'once')
% inputejeX = regexp(INPUTejeX,'[-]?\d+(\.)?(\d+)?','match','once');
EJEX=str2double([inputejeX{:}]);
ejeX=floor(sum(EJEX)/length(x));

y = floor(sum(ejeX)/length(ejeX));

if y<0%IZQUIERDA
    sentido=0;
elseif y>0%DERECHA
    sentido=1;
end
end

and the main code of the GUI is here, calling the function:

sentido=3;
            Aleatorio=1;
            while(sentido~=Aleatorio)
                for i=1:length(x);
                    data00 =fscanf(Arduino);
                    IncomingString = char(data00);
                    IncomingString = regexp(IncomingString, '\^', 'split');
                    INPUTejeXMP1(i,1)= IncomingString(1,3);

                  end
                  i=1;
  INPUTejeX=INPUTejeXMP1

                  [sentido] = giro(x,INPUTejeX)
              end

I have checked that the input value ('INPUTejeX') is being used and is full of integers. and the 'x', is this: x=[1:1:300];

someone have any idea? any comment is appreciated, since I am begining to be out of ideas and is urgent.

thank you!

Answer 1

[Stephen23]

When y is zero then you do not define sentido (and also potentially if y is not scalar, but you do not tell us anything about the values that you are using, so I will assume that y is scalar).

The simplest solution is to avoid the if statement altogether:

sentido = y>0;

Or, if you feel strongly attached to the totally unnecessary if, then you could create a separate zero case like this:

if y==0
    sentido =  ???
elseif y<0
    sentido = 0;
elseif y>0
    sentido = 1;
end

or possibly just include it in one of the other two cases, for example like this:

if y<0
    sentido = 0;
else
    sentido = 1;
end