Undefined function 'qquadrature' for input arguments of type 'double'

Can you please help:

I have the following code in an .M file:

if true
`% free vibration of non-prismatic Euler beams with or without axial load
%using differential quadrature method
clc;
ne=50;
n=ne+1;
nn=2*n;
no=4;
m=zeros(n,1);
x=zeros(n,1);
xi=zeros(n,1);
c=zeros(n,n,no);
d=zeros(n+4,n+4);
e=zeros(n+4,n+4);
z=zeros(n+4,1);
f=zeros(n+4,1);
alp=zeros(n,n);
bet=zeros(n,n);
zz=zeros(n,1);
ki=zeros(n,n);
eta=zeros(n,n);
const=1.0;
l=12;
ymod=200e09;
rho=7800;
format long;
for i=1:n
  xi(i)=0.5*(1-cos((i-1)*pi/ne));
  %mi(i)=0.000038*(1-xi(i)^2/2);
  ar(i)=1/rho;
  mi(i)=0.000038;
  ki(i,i)=ymod*mi(i);
end
c=qquadrature(xi,n,no);
%c = harquadrature(xi,n,no)
for i = 1:n
 alp(i,i) = 0;
 bet(i,i) = 0;
  for j = 1:n
      alp(i,i) = alp(i,i)+c(i,j,1)*ki(j,j)/l;
      bet(i,i) = bet(i,i)+c(i,j,2)*ki(j,j)/l^2;
  end
end
d=zeros(n+4,n+4);
% free vibration of the beam
% axial load on the beam t=+ if it is compressive t=- if it is tensile
% weight of the beam / unit length
t=520895.0;
d(1:n,1:n)=2.0*alp*c(:,:,3)/l^3+bet*c(:,:,2)/l^2+ki*c(:,:,4)/l^4+eta+t*c(:,:,2)/l^2;
% boundary conditions
% clamped - free
% d(n+1,1)=1.0;
% d(n+2:n+2,1:n)=alp(n,n)*c(n,1:n,2)/l^2+ki(n,n)*c(n,1:n,3)/l^3+t*c(n,1:n,1)/l;
% d(n+3:n+3,1:n)=c(1,1:n,1)/l;
% d(n+4:n+4,1:n)=ki(n,n)*c(n,1:n,2)/l^2;
% d(1,n+1)=1.0;
% for i=1:n
% d(i,n+2)=d(n+2,i);
% d(i,n+3)=d(n+3,i);
% d(i,n+4)=d(n+4,i);
% end
% pinned - pinned
d(n+1,1)=1.0;
d(n+2:n+2,1:n)=ki(n,n)*c(n,1:n,2)/l^2;
d(n+3:n+3,1:n)=ki(1,1)*c(1,1:n,2)/l^2;
d(n+4,n)=1.0;
d(n,n+4)=1.0;
d(1,n+1)=1.0;
d(n+4,n)=1.0;
for i = 1:n
  d(i,n+2)=d(n+2,i);
      d(i,n+3)=d(n+3,i);
end
e=zeros(n+4,n+4);
for i=1:n
e(i,i)=rho*ar(i);
end
z=d\e;
[ev,euv]=eig(z);
for i=1:n
zz(z)=ev(i,5);
end
omega=sqrt(1/euv(5,5));
sprintf(' natural frequency\n')
omega;
figure(1);
plot(xi,zz)
xlabel(' x/L ')
ylabel(' z')
title (' fundamental mode shape ')`
end

I have stored this file (Untitled.M) in the normal Matlab path, and therefore I'm assuming that Matlab will read the function when it's starting and that this function therefore should be available to use. Then I am trying to run this single M-files. But "Undefined function 'qquadrature' for input arguments of type 'double'" message appears.. Can somebody show me where's the problem and how ti fix it? Thankyou..

Answer 1

[Mischa Kim]

Note, that qquadrature() is not a built-in MATLAB function. What does MATLAB return for

 which qquadrature

If it is

 'qquadrature' not found.

either the function is not on the path or it does not exist.

[Dewi Rasdiana]

I've searched the differential quadrature m-files on internet and I found this one http://www.mathworks.com/matlabcentral/fileexchange/7170-differential-quadrature-matrix/content/Diff_Quad.m but I know it won't work because in my case i have 3 variables (xi,n,no)..

So can please help me on how to develop this script..

I'll be appreciated with your help..

[fgttyfghfh dsfgdfg]

you can use this function i hope your problem will be solved

function[y]=qquadrature(x,n,no) m=zeros(n,1); c=zeros(n,n,4); for i=1:n m(i,1)=1; for k=1:n if ((k ==i )) jk=i; else m(i,1)=m(i,1)*(x(i)-x(k)); format long end end end for i=1:n for j=1:n if(j==i) jk=i; else c(i,j,1)=m(i,1)/((x(i)-x(j))*m(j,1)); end end end for i=1:n c(i,i,1)=0.0; for j=1:n if ((i==j)) jk=i; else c(i,i,1)=c(i,i,1)-c(i,j,1); end end end for o=2:no for i=1:n for j=1:n c(i,j,o)=0.0; for k=1:n c(i,j,o)=c(i,j,o)+c(i,k,1)*c(k,j,(o-1)); end end end end c(:,:,1); y=c;