MATLAB Using multiple functions in matlab Errors

Click For Summary
The discussion revolves around a MATLAB error encountered when calling three functions related to Newton's method for phase mole fraction calculations. The error message "Not enough input arguments" indicates that the first function, Newtonphasemolefraction1, is not receiving the required parameters. The user has defined the necessary input arguments but is not passing them correctly when invoking the functions. A suggestion is made that the user should explicitly pass the arguments in the function call to avoid confusion for the compiler. Properly structuring the function calls is essential to resolve the error and ensure the program runs smoothly.
adeeyo
Messages
20
Reaction score
0
Dear All,

Please I need your assistance in solving this MATLAB problem. I will be glad to hear from you as early as possible. Thanks for your anticipated help

I have three functions

First one


function f_PR_W=Newtonphasemolefraction1(W_PR, z,C,K_PR )
f_PR=0;
for c=1:C

f_PR_W=f_PR+z(c).*(1-K_PR(c))./(1+W_PR.*(K_PR(c)-1));
end


Another function


function fdot_PR_W=Newtonphasemolefraction2(W_PR, z,C,K_PR )
fdot_PR=0;

for c=1:C
fdot_PR_W=fdot_PR+z(c).*(K_PR(c)-1).^2/(W_PR.*(K_PR(c)-1)+1).^2;

end

The third function

function [W_PR,err,k,f_PR_W]=Newton1(Newtonphasemolefraction1,Newtonphasemolef raction2,W_PR,Tol_W_PR,Tol_f_PR,maxIter)


for k=1:maxIter
p1=W_PR-Newtonphasemolefraction1(W_PR)/Newtonphasemolefraction2(W_PR);
err=abs(p1-W_PR);
relerr=2*err/(abs(p1)+Tol_W_PR);
W_PR=p1;
f_PR_W=Newtonphasemolefraction1(W_PR);
if (err<Tol_W_PR)|(relerr<Tol_W_PR)|(abs(f_PR_W)<Tol_ f_PR),break,end
end


I call the three functions using

[W_PR,err,k,f_PR_W]=Newton1(Newtonphasemolefraction1,Newtonphasemolef raction2,W_PR,Tol_W_PR,Tol_f_PR,maxIter)

I received the following error

"Error using Newtonphasemolefraction1 (line 3)
Not enough input arguments."

And all input arguments were defined: K_PR=[0.01546,0.5,1.432],W_PR=0.25,Tol_W_PR=10^-6, Tol_f_PR=10^-10, maxIter=100, z=[0.1 0.3 0.6],C=3

Please assist.


adeeyo
 
Physics news on Phys.org
adeeyo said:
function f_PR_W=Newtonphasemolefraction1(W_PR, z,C,K_PR )
I call the three functions using
[W_PR,err,k,f_PR_W]=Newton1(Newtonphasemolefraction1, Newtonphasemolefraction2,W_PR,Tol_W_PR,Tol_f_PR,maxIter)

"Error using Newtonphasemolefraction1 (line 3)
Not enough input arguments."

I don't know Matlab, but in most computer languages your would have to write something like:

[W_PR,err,k,f_PR_W]=Newton1(Newtonphasemolefraction1(a,b,c,d),
Newtonphasemolefraction2(e,f,g,h),.. etc.

because you can't assume the compiler knows what arguments you want to pass to the functions Newtonphasemolefraction1 and Newtonphasemolefraction2 if you don't tell it. It looks like the compiler is objecting that you didn't supply any arguments to those functions.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K