unresolved externals when execute the programming

[yuan]

halo.. i face problem when i execute the programming.

it appear the error as :
1.obj : error LNK2001: unresolved external symbol "double __cdecl NR::trapzd(double (__cdecl*)(double),double,double,int)" (?trapzd@NR@@YANP6ANN@ZNNH@Z)
Debug/1.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

can anyone help me ? thanks in advance .

below is the programming :

#include <iostream>
#include<iomanip>
#include<cmath>
# include<math.h>
#include<fstream>
#include "nr.h"
# include<stdio.h>
# include <stdio.h>
/*ifndef _NR_UTIL_H_
#define _NR_UTIL_H_
#include <string>
#include <cmath>
#include <complex>
#include<fstream>
#include <iostream>*/
using namespace std;

// Driver for routine trapzd
DP func(const DP x)
{ return (x*x)*(x*x-2.0)*sin(x);
}

DP fint(const DP x)
{ return 4.0*x*(x*x-7.0)*sin(x)-(pow(x,4.0)-14.0*(x*x)+28.0)*cos(x);
}

DP trapzd(DP func(const DP), const DP a, const DP b, const int n)
{ DP x,tnm,sum,del;
static DP s;
int it,j;

if(n==1)
{ return s=0.5*(b-a)*(func(a)+func(b));
}
else {
for(it=1,j=1;j<n-1;j++)

tnm=it;
del=(b-a)/tnm;
x=a+0.5*del;
for(sum=0.0,j=0;j<it;j++,x+=del)

s=0.5*(s+(b-a)*sum/tnm);
return s;
}
}
int main (void)
{ const int NMAX=14;
const DP PI02=1.570796326794896619;
int i;
DP a=0.0, b=PI02,s;

cout<<" Integral the function with 2^(n-1) points" <<endl;
cout<<" Actual value of intgral is"<< setw(10)<<(fint(b)-fint(a))<<endl;
cout<<setw(6)<<"n"<< setw(24)<<"approximate integral"<<endl;
cout<< fixed << setprecision(6);
for(i=0;i<NMAX;i++)
{ s=NR::trapzd(func,a,b,i);

cout<<setw(6)<<(i+1)<<setw(20)<<s<<endl;
}
return 0;
}

[DaemonCoder]

Check the differences between the declaration and the two calls.

 
 
DP trapzd(DP func(const DP), const DP a, const DP b, const int n)
 
 
s=NR::trapzd(func,a,b,i);
 
s=NR::trapzd(func(const DP),a,b,i);
 

The top one is coming back undefined because the linker is expecting a value to be passed to the function.

--

The one and only.... -- Uh, What am I again?