get_isohyet_coord.c

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#include "prototypes_new.h"
 
void get_isohyet_coord(char *fname,int smonth,int emonth)
 
{
 
 extern char *mon[];
 extern int isohyets_used;
 int i,j,ier,maxj,maxi,max_value,k,kk;
 float lat,lon;
 extern struct isoh *isoh;
 FILE *fp;
 char *p,kbuf[20000],fbuf[100];
 float max_lat,max_lon,delta_lat,delta_lon,total_lat,total_lon;
 
 max_value=0;
 
 isoh=(struct isoh *) calloc(1,sizeof(struct isoh));
 if(isoh==NULL) {
 
                   printf("could not allocate isoh space\n");
                   exit(1);
 
                  }          
 
 strcpy(fbuf,fname);
 strcat(fbuf,"jan");
 
 fp=fopen(fbuf,"r");
 
 if(fp==NULL) {
 
              printf("could not open %s\n",fname);
              exit(1);
 
              }
 
 
 p=fgets(kbuf,80,fp);
 
 ier=sscanf(kbuf,"%f %f %f %f %f %f",&max_lat,&max_lon,&total_lat,
                                     &total_lon,&delta_lat,&delta_lon);
 
 fclose(fp);
 
 delta_lat=delta_lat/60.;
 delta_lon=delta_lon/60.;
 
 maxi=(total_lon/delta_lon+.00001);
 maxj=(total_lat/delta_lat+.00001);
 
 isoh->maxi=maxi;
 isoh->maxj=maxj;
 isoh->max_lat=max_lat;
 isoh->max_lon=max_lon;
 isoh->total_lat=total_lat;
 isoh->total_lon=total_lon;
 isoh->delta_lat=delta_lat;
 isoh->delta_lon=delta_lon;
 
 isoh->coord=(struct icoord**) calloc(maxi,sizeof(struct icoord *));
 
 isoh->value=(short int***) calloc(12,sizeof(short int **));
 
 if(isoh->coord==NULL || isoh->value==NULL) {
 
                            printf("no memory for isoh array\n");
                            exit(1);
 
              }
 
 for(k=0;k<12;k++) {
 
        ier=is_good(k,smonth,emonth);
 
        if(ier == -1)
                   continue;
 
        isoh->value[k]=(short int **)calloc(maxi,sizeof(short int *));
 
        if(isoh->value[k]==NULL) {
 
                printf("no memory for isoh array\n");
                exit(1);
 
          }
 
      }
 
 for(i=0;i<maxi;i++) {
 
      isoh->coord[i]=(struct icoord *) calloc(maxj,sizeof(struct icoord));
 
      if(isoh->coord[i]==NULL) {
 
                printf("no memory for isoh array\n");
                exit(1);
 
          }
 
      for(k=0;k<12;k++) {
 
        ier=is_good(k,smonth,emonth);
 
        if(ier==-1)
                continue;
 
        isoh->value[k][i]=(short int *) calloc(maxj,sizeof(short int));
 
        if(isoh->value[k][i]==NULL) {
 
                printf("no memory for isoh array\n");
                exit(1);
 
          }
 
    }
 
    }
 
/*create screen coordinates */
 
/* j increments latitude  i increments longitude */
 
 for(j=0;j<maxj;j++) {
 
 for(i=0;i<maxi;i++) {
  
         lat=max_lat-(float)j*delta_lat;
         lon=max_lon-(float)i*delta_lon;
 
         get_isoh_pixels(i,j,lat,lon);
 
    }
 
}
 
for(k=0;k<12;k++) {
 
 ier=is_good(k,smonth,emonth);
 
 if(ier==-1)
         continue;
 
 sprintf(fbuf,"%s%s",fname,mon[k]);
 
 fp=fopen(fbuf,"r");
 
 if(fp==NULL) {
 
              printf("could not open %s\n",fbuf);
              exit(1);
 
              }
 
 p=fgets(kbuf,80,fp);
 
 
/* read in data file */
/* i is longitude j is latitude */
 
 for(j=0;j<maxj;j++) {
 
 fread(kbuf,sizeof(char),maxi*5,fp);
 kbuf[maxi*5]=0; 
 kk=0;
 
/* read in longitude records */
 
 for(i=0;i<maxi;i++) {
  
         isoh->value[k][i][j]=atoi(&kbuf[kk]);
        
         kk=kk+5;
 
    }
 
}
 
fclose(fp);
 
}
 
isohyets_used=1;
return;
 
}
void get_isoh_pixels(int i, int j, float lat,float lon)
 
  {
 
     extern struct dval dval;
     long r,s;
     float conv=.0174;
     extern struct isoh *isoh;
 
 
     
     r=dval.a * cos(lat*conv)/(1+sin(lat*conv))
       * cos((lon-dval.lo-90)*conv) + dval.xo +.5;
 
     isoh->coord[i][j].x=r;
 
     s=dval.a * cos(lat*conv)/(1+sin(lat*conv))
       * sin((lon-dval.lo-90)*conv) + dval.yo + .5;
       
     isoh->coord[i][j].y=s;
 
     return;
 
   }