#include<stdio.h>
#include<stdlib.h>
#include<math.h>
//#include<malloc.h>
#include <string.h>

int main()
{
	double	r=0.011237;   //  standard ratio of c13/c12 -- based on Pee Dee Belemnite
	double c13r1,c13r2,sm;
	int s,yy;
	int vy,vd;
	float vco2[66],vc13[66],wv;
	char ls_fn[80],x2_fn[98],x3_fn[98];		
	FILE *x2_ptr,*x3_ptr,*ls_ptr;		


	sprintf(ls_fn,"../co2change_x_Ra73stn42m.txt");

	if ((ls_ptr=fopen(ls_fn, "w")) == NULL)
		{ printf("\n Unable to open  listing file,  exitting program ...\n\n");
			  exit(0);
		}

	printf("processing ...  \n");

	for (s=1;s<=73;s++)
	{
	sm=0;
	sprintf(x2_fn,"../data_co2c13obs/co2_msr_monthly_stn%d.txt",s);
	if ((x2_ptr=fopen(x2_fn, "r")) == NULL)
		{ printf("\n Unable to open  input2 file,  exitting program ...\n\n");
			  exit(0);
		}
	
	sprintf(x3_fn,"../data_co2c13obs/c13_msr_monthly_stn%d.txt",s);
	if ((x3_ptr=fopen(x3_fn, "r")) == NULL)
		{ printf("\n Unable to open  input3 file,  exitting ...\n\n");
			  exit(0);
		}
		
		for (yy=1;yy<=60;yy++)    // 5yr x 12mn 
		{
		fscanf(x2_ptr,"%d %d %f\n",&vy,&vd,&vco2[yy]);
		fscanf(x3_ptr,"%d %d %f\n",&vy,&vd,&vc13[yy]);
		}

                for (yy=2;yy<=60;yy++)   
                {
		//  convering obs. values dlt to R 
		c13r1=(vc13[yy-1]*0.001+1)*r;
		c13r2=(vc13[yy]*0.001+1)*r;

		wv=(float)(0.011147*(vco2[yy]-vco2[yy-1]));
	sm = sm +wv;	
//	if (yy>18)	fprintf(ls_ptr,"%d\t%d \t %f\n",s,yy,sm);
	if (yy>18)      fprintf(ls_ptr,"%d\t%d \t %f\n",s,yy,wv);	
		}	

	fclose(x2_ptr);
	fclose(x3_ptr);
	}  // end of s

//	fprintf(ls_ptr,"avg:  %f\n",sm/73);
	fclose(ls_ptr);

return 1;
}