how to output inputname from varargin

Hi, I have a set of input arguments. I want to loop through one of them so i make the one (n) i want to loop a vector. Then I wrote a function file to test which one is the vector so matlab knows which one to loop. But I am having a problem bringing out the output as a variable from this function to then carry on with the loop.

rt = 3;       
Ps = 5.3;
tt = 600;
Tjh =  1; 
Tjc = 18; 
n=[5,6,8,9];                 
tad=0.01328;            
mc=0.001566;            
ps=30;             
dt=0.002;              
A = 0.09;                  
Ay = 2;               
Kad=4;                
h=844;     
     function p= intest(varargin)
for i = 1:nargin
    va(i)=(length(varargin{i}));
end
w=find(va>1);
p=inputname(w);
end
 for....

Thanks.

Answer 1

[Stephen23]

With so many variables it would be a good idea to store them in a structure anyway, to avoid workspace clutter and to make passing and storing those variables much simpler. And when these variables are stored in a structure it also makes your task easy:

S.rt = 3;
S.Ps = 5.3;
S.tt = 600;
S.Tjh =  1;
S.Tjc = 18;
S.n=[5,6,8,9];
S.tad=0.01328;
S.mc=0.001566;
S.ps=30;
S.dt=0.002;
S.A = 0.09;
S.Ay = 2;
S.Kad=4;
S.h=844;
%
V = structfun(@numel,S);
C = fieldnames(S);
assert(nnz(V>1)==1,'Too many vectors')
for k = S.(C{V>1})
    disp(k)
end

this detects that S.n is a vector, and prints its values in the loop:

5
6
8
9

[Oluyemi Jegede]

Thanks. But I have a body of code in the for loop where the variable n is used. Would this still work in that case?

[Stephen23]

If you want to loop over all of the scalar elements/values in S.n, but want to use the same fieldname inside the loop, then you can do this:

N = structfun(@numel,S); % number of elements
assert(nnz(N>1)==1,'Too many vectors')
C = fieldnames(S);
F = C{N>1}; % fieldname of non-scalar field.
V = S.(F);  % data from that field
for k = V
    S.(F) = k;
    S.n % each scalar value of S.n
    ... code that uses all scalar values.
end

which in the loop prints each scalar value of S.n:

ans =  5
ans =  6
ans =  8
ans =  9

Inside the loop every variable will have to be replaced with the equivalent S.xxx.

[Oluyemi Jegede]

thanks!!!

[Stephen23]

My pleasure! You can also accept the Answer that best resolves your question.