#include <stdio.h>
#include <stdlib.h>
#include <math.h>
typedef struct values_s
{
double *x;
double *funcval ;
double *derivate ;
long size ;
} values_t ;
values_t * values_allocate (long size )
{
values_t *elem;
if(!(elem=calloc(1,sizeof(values_t))))
{
fprintf(stderr,"Fehler bei Speicherallozierung!\n");
return 0;
}
elem->size=size;
if(!(elem->x=calloc(size,sizeof(double))))
{
fprintf(stderr,"Fehler bei Speicherallozierung!\n");
free(elem);
return 0;
}
if(!(elem->funcval=calloc(size,sizeof(double))))
{
fprintf(stderr,"Fehler bei Speicherallozierung!\n");
free(elem->x);
free(elem);
return 0;
}
if(!(elem->derivate=calloc(size,sizeof(double))))
{
fprintf(stderr,"Fehler bei Speicherallozierung!\n");
free(elem->x);
free(elem->funcval);
free(elem);
return 0;
}
return elem;
}
typedef enum boolean_e
{
FALSE = 0,
TRUE = 1
} boolean_t ;
boolean_t values_insert ( values_t *val , double x1 , double x2 , double x3 , long index )
{
if(val==0||index<0||index>=val->size)
return FALSE;
val->x[index]=x1;
val->funcval[index]=x2;
val->derivate[index]=x3;
return TRUE;
}
boolean_t values_free ( values_t *val)
{
if(val==0)
return FALSE;
free(val->derivate);
val->derivate=0;
free(val->funcval);
val->funcval=0;
free(val->x);
val->x=0;
free(val);
return TRUE;
}
boolean_t values_print ( values_t *val)
{
if(val==0)
return FALSE;
long i;
for(i=0;i<val->size;i++)
printf("%3ld: %10g | %10g %10g\n",i,val->x[i],val->funcval[i],val->derivate[i]);
return TRUE;
}
double function1(double x)
{
return pow(x,4)+6*pow(x,2)-1;
}
double function2(double x)
{
return cos(x);
}
double function3(double x)
{
return exp(pow(x,2));
}
double function4(double x)
{
return sqrt(pow(x,2)+3);
}
typedef double (*func_t)(double);
boolean_t differentiate ( values_t *val , func_t func )
{
if(val==0)
return FALSE;
long i;
for(i=0;i<val->size;i++)
val->funcval[i]=func(val->x[i]);
for(i=0;i<val->size;i++)
{
if(!(val->x[i+1]-val->x[i-1]))
{
fprintf(stderr,"Division durch 0!\n");
return FALSE;
}
val->derivate[i]=(val->funcval[i+1]-val->funcval[i-1])/(val->x[i+1]-val->x[i-1]);
}
return TRUE;
}
boolean_t values_save ( values_t *val , char *file )
{
if(val==0)
return FALSE;
FILE *f;
if(!(f=fopen(file,"w")))
return FALSE;
long i;
for(i=0;i<val->size;i++)
fprintf(f,"%3ld: %10g | %10g %10g\n",i,val->x[i],val->funcval[i],val->derivate[i]);
fclose(f);
return TRUE;
}
double function5(double x)
{
return atan(x)*x;
}
int main()
{
printf("Nummerisches Differenzieren!\n");
values_t *elem=values_allocate(20);
//double x=3;
long i;
double ug=0,og=5;
double dx=(og-ug)/elem->size;
for(i=0;i<elem->size;i++,ug+=dx)
values_insert(elem,ug,0,0,i);//hier habe ich verändert
differentiate(elem,function1);
values_print(elem);
if(values_save(elem,"test.txt")!=TRUE)
fprintf(stderr,"Fehler beim Speichern!\n");
if(values_free(elem)!=TRUE)
{
fprintf(stderr,"Fehler bei Speicherfreigabe!\n");
exit(-1);
}
elem=0;
return 0;
}
