Drawing a complex function with GNU Plot

I am working in a research laboratory and my tutor asked me to draw the langerman statistic function with GNUPlot.

Hi gave me this code, that should be able to generate the cordinate.

#include "stdafx.h"
#include "fitness.h"
#include "function.h"
double temp1(double d1, double d0);
double temp2(double d0);
//double RozenBrock(double *x, int n);
double RozenBrock(vector<GeneType> a, int n);
double langerman(vector<GeneType> x,int nn);

double Share_Com_Fitness(GANode<GeneType> Node)
{
 double r=0.0;

 /*for(int i=0;i!=Node.Show_Gene_Num();i++)
 {

 }*/
 r=RozenBrock(Node.gene,Node.Show_Gene_Num());

 //r=langerman(Node.gene,Node.Show_Gene_Num());

 return r;
}

//RozenBrock 函数
double temp1(double d1, double d0)
{
   return (d1 - d0*d0);
}

double temp2(double d0)
{
     return (1. - d0);
}

//double RozenBrock(double *x, int n)
double RozenBrock(vector<GeneType> x, int n)
{ 
   double t0, tt, t1, d=0;
   int i;

   t0=x[0];
   for ( i=1; i < n; i++) 
   {
      t1 = x[i];
      tt = temp2(t0);
      d += tt*tt;
      tt = temp1(t1,t0);
      d += 100*tt*tt;

      t0 = t1;
   }

   return(-d);
}
//end RozenBrock 函数

//Langerman  函数
double a[30][10] = {
 {9.681, 0.667, 4.783, 9.095, 3.517, 9.325, 6.544, 0.211, 5.122, 2.020},
 {9.400, 2.041, 3.788, 7.931, 2.882, 2.672, 3.568, 1.284, 7.033, 7.374},
 {8.025, 9.152, 5.114, 7.621, 4.564, 4.711, 2.996, 6.126, 0.734, 4.982},
 {2.196, 0.415, 5.649, 6.979, 9.510, 9.166, 6.304, 6.054, 9.377, 1.426},
 {8.074, 8.777, 3.467, 1.863, 6.708, 6.349, 4.534, 0.276, 7.633, 1.567},
 {7.650, 5.658, 0.720, 2.764, 3.278, 5.283, 7.474, 6.274, 1.409, 8.208},
 {1.256, 3.605, 8.623, 6.905, 0.584, 8.133, 6.071, 6.888, 4.187, 5.448},
 {8.314, 2.261, 4.224, 1.781, 4.124, 0.932, 8.129, 8.658, 1.208, 5.762},
 {0.226, 8.858, 1.420, 0.945, 1.622, 4.698, 6.228, 9.096, 0.972, 7.637},
 {7.305, 2.228, 1.242, 5.928, 9.133, 1.826, 4.060, 5.204, 8.713, 8.247},
 {0.652, 7.027, 0.508, 4.876, 8.807, 4.632, 5.808, 6.937, 3.291, 7.016},
 {2.699, 3.516, 5.874, 4.119, 4.461, 7.496, 8.817, 0.690, 6.593, 9.789},
 {8.327, 3.897, 2.017, 9.570, 9.825, 1.150, 1.395, 3.885, 6.354, 0.109},
 {2.132, 7.006, 7.136, 2.641, 1.882, 5.943, 7.273, 7.691, 2.880, 0.564},
 {4.707, 5.579, 4.080, 0.581, 9.698, 8.542, 8.077, 8.515, 9.231, 4.670},
 {8.304, 7.559, 8.567, 0.322, 7.128, 8.392, 1.472, 8.524, 2.277, 7.826},
 {8.632, 4.409, 4.832, 5.768, 7.050, 6.715, 1.711, 4.323, 4.405, 4.591},
 {4.887, 9.112, 0.170, 8.967, 9.693, 9.867, 7.508, 7.770, 8.382, 6.740},
 {2.440, 6.686, 4.299, 1.007, 7.008, 1.427, 9.398, 8.480, 9.950, 1.675},
 {6.306, 8.583, 6.084, 1.138, 4.350, 3.134, 7.853, 6.061, 7.457, 2.258},
 {0.652, 2.343, 1.370, 0.821, 1.310, 1.063, 0.689, 8.819, 8.833, 9.070},
 {5.558, 1.272, 5.756, 9.857, 2.279, 2.764, 1.284, 1.677, 1.244, 1.234},
 {3.352, 7.549, 9.817, 9.437, 8.687, 4.167, 2.570, 6.540, 0.228, 0.027},
 {8.798, 0.880, 2.370, 0.168, 1.701, 3.680, 1.231, 2.390, 2.499, 0.064},
 {1.460, 8.057, 1.336, 7.217, 7.914, 3.615, 9.981, 9.198, 5.292, 1.224},
 {0.432, 8.645, 8.774, 0.249, 8.081, 7.461, 4.416, 0.652, 4.002, 4.644},
 {0.679, 2.800, 5.523, 3.049, 2.968, 7.225, 6.730, 4.199, 9.614, 9.229},
 {4.263, 1.074, 7.286, 5.599, 8.291, 5.200, 9.214, 8.272, 4.398, 4.506},
 {9.496, 4.830, 3.150, 8.270, 5.079, 1.231, 5.731, 9.494, 1.883, 9.732},
 {4.138, 2.562, 2.532, 9.661, 5.611, 5.500, 6.886, 2.341, 9.699, 6.500}};


double c[] = {
        0.806,
 0.517,
 0.1,
 0.908,
 0.965,
 0.669,
 0.524,
 0.902,
 0.531,
 0.876,
 0.462,
 0.491,
 0.463,
 0.714,
 0.352,
 0.869,
 0.813,
 0.811,
 0.828,
 0.964,
 0.789,
 0.360,
 0.369,
 0.992,
 0.332,
 0.817,
 0.632,
 0.883,
 0.608,
 0.326};


//double RozenBrock(vector<GeneType> x, int n)
//double langerman(double x[],int nn)
double langerman(vector<GeneType> x,int nn)  /* Langerman's function */
{

     int  i,j;

     double   Sum,d,
                 PI,
                 dist,
   temp1,
   temp2,
   temp20,temp21 ;


 PI  = 3.141592653; 
 Sum = 0.0;




 for ( i = 0; i < 5; i++ )
 { 
  dist = 0.0;
  for ( j= 0; j<nn; j++ )
    {
       d =x[j] - a[i][j];
   temp1=(d*d);
       dist =dist +temp1;
   //printf("%1f*%1f|",x[j],a[i][j]);
    }

      //dist = SqrDst(x, a[i], nn);
  temp20=exp(-dist/PI);
  temp21=cos( PI * dist ) ;
      temp2=c[i] * (temp20*temp21);
  //printf("\n dist=%1f ++ %1f,%1f,%1f \n",dist,temp20,temp21,temp2);

      Sum -= temp2;
  //printf("\nSum=*%1f**",-Sum);

 }
 //printf("\n E Sum=*%1f**",Sum);
     return (-(double)(Sum/5.0));
}

//end Langerman  函数

http://www.siteduzero.com/uploads/fr/files/192001_193000/192917.png

Do you have any idea. Of how I could do that ? I was thinking maybe by using GNU/Octave to generate the coordinate and startploting from octave with GNUPlot.

Best regards,

Natim