Matlab Error: Too many output arguments

Question

I use the following function in a Matlab program:

...
...
...
[A, B, C, D, E] = function (F, G, H, I, J, K, L, M, N, O, P)
...
...
...
and I get the following error message:

??? Error using ==> function
Too many output arguments.

A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P are the vectors of inputs and outputs of the function.

but the same program works very well when I replaced the line of the function by its full script!
Can you tell me where I should look to find the error..

Answer 1

Did you call your function function? This is a VERY BAD idea, since function is a reserved key word.

Assuming you have simply replaced the name of the function you want to call with 'function' in your example: You need to define input and output in the function definition. For example, for a function called 'myFun', which accepts F-P as inputs, and should return A-E as outputs, you write as the first line of the function

function [A,B,C,D,E] = myFun(F,G,H,I,J,K,L,M,N,O,P)

EDIT

To clarify: You get the error because you're asking for more output arguments than the function can supply. You'd get the same error if you'd call [u,v]=sin(0), since sin is defined with 1 output only. Thus, you have to check your function's signature to solve the problem.

EDIT 2

Let's make an example

I open the editor and define the function

function [A,B,C] = myFun(D,E,F)
%# myFun returs the pairwise sums of the input arguments

A = D+E;
B = E+F;
C = F+D;

Then, I save the function as "myFun.mat" on the Matlab path.

Now I can call myFun like so:

[A,B,C] = myFun(1,2,3);

However, if I call myFun with four output arguments, I'll get an error

[A,B,C,D] = myFun(1,2,3);

In fact, I get exactly the error you got, because I only defined myFun with three output arguments.

Note: You can always call a function with fewer than the number of defined output arguments, but never with more.

Answer 2

I tried to test the program with a single output each time for A, B, C, D, E:
function [A] = myFun1 (F, G, H, I, J, K, L, M, N, O, P)
function [B] = myFun2 (F, G, H, I, J, K, L, M, N, O, P)
function [C] = myFun3 (F, G, H, I, J, K, L, M, N, O, P)
function [D] = myFun4 (F, G, H, I, J, K, L, M, N, O, P)
function [E] = myFun5 (F, G, H, I, J, K, L, M, N, O, P)

it works and the program works well, but the output is the only difference between the 5 functions myFun1, myFun2, myFun3, myFun4, myFun5.
I think this is not practical.
So is there any way to have a single function myfun with 5 outputs?

Answer 3

my program:

clc;
clear all;

load('C:\Users\Documents\MATLAB\myFile\matrice_F.mat');
load('C:\Users\Documents\MATLAB\myFile\matrice_G.mat');
load('C:\Users\Documents\MATLAB\myFile\matrice_H.mat');
load('C:\Users\Documents\MATLAB\myFile\matrice_I.mat');
F = m_F;
G = m_G;
H = m_H;
I = m_I;

load('C:\Users\Documents\MATLAB\myFile\matrice_J.mat');
load('C:\Users\Documents\MATLAB\myFile\matrice_K.mat');
load('C:\Users\Documents\MATLAB\myFile\matrice_L.mat');
load('C:\Users\Documents\MATLAB\myFile\matrice_M.mat');
J = m_J;
K = m_K;
L = m_L;
M = m_M;

load('C:\Users\Documents\MATLAB\myFile\matrice_Result.mat');
N = m_N ;
O = m_O;
P = m_P;

[A,B,C,D,E] = myFun(F,G,H,I,J,K,L,M,N,O,P);

file_name = 'matrice_final.mat';
save(file_name,'A','B','C','D','E');

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
my Function:

function %matrice_return% [AA,BB,CC,DD,EE] = myFun(Q,R,S,T,U,V,W,X,Y,Z,ZZ)

AA=zeros(1,10);
BB=zeros(1,10);
CC=zeros(1,10);
DD=zeros(1,10);
EE=zeros(1,10);

for i=1:1:10

    if  Q(i)>1   
        AA(i)=R(i)*S(i);  
    end  
    if  R(i)>1   
        BB(i)=T(i)*U(i);              
    end  
    if  S(i)>1   
        CC(i)=V(i)*W(i);              
    end  
    if  T(i)>1   
        DD(i)=X(i)*Y(i);              
    end  
    if  U(i)>1   
        EE(i)=Z(i)*ZZ(i);              
    end  

end

%matrice_return = [AA,BB,CC,DD,EE];% %%error

my problem is solved, I thank all those who gave their time to solve my problem. I did not expect that the solution is so simple!!

Answer 4

I assume that your function really has 5 output arguments. If so, there is probably some other function with the same name in the Matlab Path with a different number of output arguments. Happens to me also now and then if I create functions with the same name but more or less output arguments.

As I see you load data from a specified path. Maybe you are not in the folder with the function you really want to call.

Try renaming your function (file + function name inside). Also try to Set Path to default (File->Set Path...-> Default) and change directory to the directory with your function. If none of this works then try all steps again, I'm pretty sure that's the reason for your errors.

Answer 5

@lebland

The code you posted defines a function with one return variable called matrice_return. It seems that you want to return the five variables AA,BB,CC,DD,EE. So now edit your function definition as @Jonas has explained very clearly. if you had posted your definition in your question we would have sorted this out hours ago.

Answer 6

Your problem is with the matrice_return variable. Instead of:

function matrice_return = myFun(Q,R,S,T,U,V,W,X,Y,Z,ZZ) 
.
.
.
matrice_return = [AA,BB,CC,DD,EE];

try:

function [AA,BB,CC,DD,EE] = myFun(Q,R,S,T,U,V,W,X,Y,Z,ZZ)

Answer 7

If you don't want to change myFun definition, you can do the following in your script:

myFun_result = myFun(F,G,H,I,J,K,L,M,N,O,P);
A = myFun_result(1:10);
B = myFun_result(11:20);
C = myFun_result(21:30);
D = myFun_result(31:40);
E = myFun_result(41:50);