/*
# correggi_tc.c
#
# (C) Luca Barion 2010
# Last modified: 2012-09-12 15:01
#
*/

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

// 0-76 K (CLTS)
#define P0     -7920.91
#define P1       481.92
#define P2     -11.7329
#define P3     0.142982
#define P4 -0.000869082
#define P5  2.10627E-06
// 76-110 K (CLTS)
#define Q0     -478.932
#define Q1      15.8473
#define Q2    -0.197846
#define Q3    0.0012728
#define Q4 -3.21378e-06
// 110-280 K (CLTS)
#define R0     -111.300
#define R1      2.56908
#define R2  -0.00839146
#define R3  1.93376e-05
#define R4 -1.58789e-08


// Functions prototypes
void print_help(void);
float correggi(float tc);


/*** Main ***/
int main(int argc, char *argv[])
{
FILE *fp;
char buf[32];
int i;
float tc;

fprintf(stderr, "correggi_tc - (C) 2010 Luca Barion\n");
 
if (argc == 2)
  {
   if (strcmp(argv[1],"-h")==0) print_help();
  }
 else
  {
   print_help();
   return 0;
  }

fp=fopen(argv[1],"r");
 if (fp==NULL) {perror("fopen"); return -1;}

fprintf(stderr, "Reading from %s...\n", argv[1]);
sleep(2);
fgets(buf, 32,fp);
printf("%s",buf);
i=1;
while (i>0)
  {
   i=fscanf(fp, "%f\n", &tc);
   if (i<=0) continue;
   printf("%3.2f\n", correggi(tc) );
   fprintf(stderr, " \\=> tc_raw: %3.2f\n", tc);
  }

return 0;
}


/*
    /////////|\\\\\\\\\
   <**** Functions ****>
    \\\\\\\\\|/////////
*/

float correggi(float tc)
{
float tc_corrected;

if (tc<98)
  tc_corrected= P0 + P1*tc + P2*pow(tc,2) + P3*pow(tc,3) + P4*pow(tc,4) + P5*pow(tc,5);
 else
  {
   if (tc<121.7)
     tc_corrected= Q0 + Q1*tc + Q2*pow(tc,2) + Q3*pow(tc,3) + Q4*pow(tc,4);
    else
     tc_corrected= R0 + R1*tc + R2*pow(tc,2) + R3*pow(tc,3) + R4*pow(tc,4);
  }

return (tc_corrected);
}


void print_help(void)
{
 printf("usage: correggi_tc <file> [ > <output_file> ]\n"
        "(eg. correggi_tc input.txt > output.txt)\n"
        "\n");

 exit(0);
}