Thread: Errors with array

I am trying to run a C source code about Evolutionary Programming.
I get these errors after the compilation.
Anyone can help me to fix it? I am using VC 2005.
I need help urgently.


Here is the error part:--

Code:

double function14(int n)
{
double value;
int i,j;

double sum1,sum2,prod;

double a[n][25];

for(j=0;j<25;j=j+5)
{
a[0][j]=-32.0;
a[0][j+1]=-16.0;
a[0][j+2]=0.0;
a[0][j+3]=16.0;
a[0][j+4]=32.0;
}

error C2057: expected constant expression
error C2466: cannot allocate an array of constant size 0
error C2133: 'a' : unknown size


Thanks everyone

Originally Posted by cpjust

Code:

double a[n][25];

You can't use a variable as an array size when you declare an array. (except in C99 which most compilers don't support yet).

Thanks for your quick response.
Actually i downloaded this program from internet.
I am trying to run it in my pc for studying about the Evolutionary Programming.

So i need to run it without changing the functions of this program.

Do you have any suggestion for me to make it run in my pc?

Thanks a lot.

Use malloc to dynamically create this array.

You could initialize a[n][25] with a constant value for n that is bigger than you would expect to see (I don't know what the function is for so I can't suggest one). You can use n everywhere else, though.

Or, to save space, you can make a[n] (where n is a large number) and have each index be a pointer to an array b[25].

i.e.,

Code:

double *a[255]
double b[25]
a[0]=b

I think this will work, correct me if I'm wrong.

Code:

double function19(int n)
{
  double value;
  int i,j;
  double sum1,sum2;
  double a[4][n],p[4][n];
  double c[4];
 

 

/* assign the values of left and right boundary  */
  for(i=0;i<n;i++)
  {
    left_bound[i]=0;
    right_bound[i]=1;
  }


    
    a[0][0]=3.0;
    a[0][1]=10.0;
    a[0][2]=30.0;

    a[1][0]=0.1;
    a[1][1]=10.0;
    a[1][2]=35.0;

    a[2][0]=3.0;
    a[2][1]=10.0;
    a[2][2]=30.0;

    a[3][0]=0.1;
    a[3][1]=10.0;
    a[3][2]=35.0;

    c[0]=1;
    c[1]=1.2;
    c[2]=3;
    c[3]=3.2;

    p[0][0]=0.3689;
    p[0][1]=0.1170;
    p[0][2]=0.2673;

    p[1][0]=0.4699;
    p[1][1]=0.4387;
    p[1][2]=0.7470;

    p[2][0]=0.1091;
    p[2][1]=0.8732;
    p[2][2]=0.5547;

    p[3][0]=0.038150;
    p[3][1]=0.5743;
    p[3][2]=0.8828; 
  
 sum1=0.0;
 
 for(i=0;i<4;i++)
 {
   sum2=0.0;
   
   for(j=0;j<n;j++)
   {
     sum2=sum2+a[i][j]*pow(z[j]-p[i][j],2.0);
   }
   sum1=sum1+c[i]*exp(-sum2);
 }
 value=-sum1;
 return value;
}

I am having the same errors for this part.
So sorry for the silly questions, i'm a beginner in C programming.

Thanks again to everyone.
Now i am facing another errors in my program.

Code:

void initilization(int n)
{
  int i,j;
  double segment;
 
  unsigned int start_time;

  time_t time1;

  (void) time(&time1);
  start_time=(int)time1;
  srand(start_time);

  for(j=0;j<max_n;j++)
  {
    z[j]=0.0;
  }

  for(i=0;i<population_size;i++)
  {
    individual_f[i]=function1(n);
  }

/* assign the initial values of points */

  for(i=0;i<population_size;i++)
  {
    for(j=0;j<n;j++)
    {
      individual_x[i][j]=left_bound[j]+rand()%10*0.1*(right_bound[j]-left_bound[j]);
      new_individual_x[i][j]=individual_x[i][j];
    }
  }

/* compute their fitness */
  for(i=0;i<population_size;i++)
  {
    for(j=0;j<n;j++)
    {
      z[j]=individual_x[i][j];
    }
    individual_f[i]=function(n);
    new_individual_f[i]=individual_f[i];
    //   printf("\n fitness[%d]=%10.5f",i,individual_f[i]);
  }

  /* assign the initial values of sigmas */
  

  
  for(i=0;i<population_size;i++)
  {
    
    for(j=0;j<n;j++)
    {
      individual_sigma[i][j]=3.0;//sqrt(0.1*(right_bound[j]-left_bound[j]));
      new_individual_sigma[i][j]=individual_sigma[i][j];
     }
  }

/* assign the initial values of mixed distribution */
  for(i=0;i<population_size;i++)
  {
    individual_mp[i]=rand()%no_strategy;
    new_individual_mp[i]=individual_mp[i];

  }
  for(i=0;i<no_strategy;i++)
  {
    for(j=0;j<no_strategy;j++)
    {
        p_history[i][j]=1.0/(double)no_strategy;
    }
  }
  /* assign the performance of each strategy a non-zero tiny positive */
  for(i=0;i<no_strategy;i++)
  {
    performance_of_best_mp[i]= 1.0e-10;
  }
}

error LNK2019: unresolved external symbol _function referenced in function _initilization
fatal error LNK1120: 1 unresolved externals

How can i fix this error?

The function have implemented here

Code:

double function1(int n)
{
  double value;
  int i,j;

/* assign the values of left and right boundary  */
  for(j=0;j<n;j++)
  {
    left_bound[j]=-100.0;
    right_bound[j]=100.0;
  }
  value =0.0;
  for(j=0;j<n;j++)
  {
    value=z[j]*z[j]+value;
  }
  return value;
}


/* function  9 (5 in Lee)*/
double function9(int n)
{
  double value;
  int i,j;



/* assign the values of left and right boundary  */
  for(j=0;j<n;j++)
  {
    left_bound[j]=-5.12;
    right_bound[j]=5.12;
  }

  value =0.0;
  for(i=0;i<n;i++)
  {
    value=z[i]*z[i]-10.0*cos(2*M_PI*z[i])+10.0+value;
  }
  return value;
}

but still not working. Thanks for your comments.

Originally Posted by BEN10

What errors are you getting now?

The error is this:
error LNK2019: unresolved external symbol _function referenced in function _initilization
fatal error LNK1120: 1 unresolved externals

It seems you have function1 and function9 defined, but I don't function. You need to define function without any numbers, or you have a typo in your code

Code:

    individual_f[i]=function(n);