function in matlab- undefined input argument error - matlab

Question

I can't understand what the problem is with this code. If anyone can help I will be thankful.
function [out] = detj(in1)
%DETJ Summary of this function goes here
%Detailed explanation goes here: N is 2*50 matrix and in1 is scaler
global N
out=(1/8)*(N(1,in1));
end
The error is :
Input argument "in1" is undefined.
Error in ==> detj at 7
out=(1/8)*(N(1,in1));
I defined N in another file
N=importdata('Nodes.txt'); %Matrix of nodes

Answer 1

No thing wrong with your code, you just used the function the wrong way.
To use a Function in Matlab you need to call it, NOT to run it directly.
This is your original function code
function [out] = detj(in1,in2,in3,in4)
%DETJ Summary of this function goes here
% Detailed explanation goes here %N is 2*50 Matrix
global N r s
out=zeros(2,2);
for m=1:2
for n=1:2
out(m,n)=(1/8)*(((N(1,in1)-N(1,in3))*(N(2,in2)-N(2,in4))-(N(2,in1)-N(2,in3))*(N(1,in2)-N(1,in4)))-r(1,m)*((N(1,in3)-N(1,in4))*(N(2,in1)-N(2,in2))-(N(2,in3)-N(2,in4))*(N(1,in1)-N(1,in2)))+s(1,n)*((N(1,in2)-N(1,in3))*(N(2,in1)-N(2,in4))-(N(2,in2)-N(2,in3))*(N(1,in1)-N(1,in4))));
end
end
end
To use your function I tried a simple code,
clc;clear;
global N
global r
global s
N=ones(2,50);
r=ones(2,2);
s=ones(2,2);
detj(1,2,3,4)
And I got answer as
ans =
0 0
0 0
So no thing wrong with your function, just you need to know how to use it.
Let me know if my answer is not clear else good luck.