halflife.c

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#include "libtpcmisc.h"
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static char *isotope_code[] = {
  "Br-75", "Br-76", "Cu-62", "Cu-64", "Fe-52",
  "Ga-68", "Ge-68", "Na-22", "Rb-82", "Zn-62",
  "F-18",  "C-11",  "N-13",  "O-15",  "O-14", "I-124",
0};
static double isotope_halflife[] = {
  HL_Br75, HL_Br76, HL_Cu62, HL_Cu64, HL_Fe52,
  HL_Ga68, HL_Ge68, HL_Na22, HL_Rb82, HL_Zn62,
  HL_F18,  HL_C11,  HL_N13,  HL_O15,  HL_O14, HL_I124,
  0.0
};
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char *hlIsotopeCode(int isotope) {
  static char unknown_isotope[]="unknown";
  int n=0;
  
  while(isotope_code[n]!=0) n++;
  if(isotope<0 || isotope>n-1) return(unknown_isotope);
  else return(isotope_code[isotope]);
}
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double hlFromIsotope(
  char *isocode
) {
  char *corrected_isocode;
  int i = 0;
  int ok = 0;
 
  /* Validate the isotope string */
  corrected_isocode=hlCorrectIsotopeCode(isocode);
  if(corrected_isocode==NULL) return(-1.0);
 
  /* Determine the isotope and return the half-life */
  while(isotope_code[i]!=0) {
    if(strcmp(isotope_code[i], corrected_isocode)==0) {ok=1; break;}
    i++;
  }
  if(ok==1) return(isotope_halflife[i]);
  else return(-2.0);
} 
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double hl2lambda(double halflife) {
  if(halflife>0.0) return(M_LN2/halflife); else return(-1.0); // M_LN2=log(2.0)
}
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double hlLambda2factor(double lambda, double frametime, double framedur) {
  double cf, ff;
 
  if(frametime<0) return(-1.0);
  cf=exp(lambda*frametime);
  if(framedur>1.0E-5) {
    ff=fabs(lambda)*framedur/(1.0-exp(-fabs(lambda)*framedur));
    if(lambda<0.0) cf/=ff; else cf*=ff;
  }
  return(cf);
}
float hlLambda2factor_float(float lambda, float frametime, float framedur) {
  float cf, ff;
 
  if(frametime<0) return(-1.0);
  cf=exp(lambda*frametime);
  if(framedur>1.0E-5) {
    ff=fabs(lambda)*framedur/(1.0-exp(-fabs(lambda)*framedur));
    if(lambda<0.0) cf/=ff; else cf*=ff;
  }
  return(cf);
}  
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char *hlCorrectIsotopeCode(char *isocode) {
  int i, ok=0, n, mass_nr=0, ic_mass_nr=0;
  char *cptr, atom[3], ic_atom[3];
 
  /* Check, if isocode can be found in the list */
  i=ok=0;
  while(isotope_code[i]!=0) {
    if(strcasecmp(isotope_code[i], isocode)==0) {
      ok=1;
  break;
    }
    i++;
  }
  if(ok==1) return(isotope_code[i]);
 
  /* Try to figure out what it is */
  /* Separate the atom name and mass number */
  n=strcspn(isocode, "-1234567890");
  if(n>2) { /* cannot be */
    return(NULL);
  } else if(n>0) { /* start with atom name */
    strncpy(atom, isocode, n); atom[n]=(char)0;
    mass_nr=atoi(isocode+n); if(mass_nr<0) mass_nr=-mass_nr;
  } else { /* starts with mass number */
    mass_nr=atoi(isocode);
    cptr=isocode; while(isdigit((int)cptr[0])) cptr++;
    if(strlen(cptr)>2) return(NULL);
    strcpy(atom, cptr); 
  }
  /* Check if it matches any of the listed isotopes */
  i=ok=0;
  while(isotope_code[i]!=0) {
    /* Separate the atom name and mass number from the listed isotope */
    n=strcspn(isotope_code[i], "-1234567890");
    strncpy(ic_atom, isotope_code[i], n); ic_atom[n]=(char)0;
    ic_mass_nr=atoi(isotope_code[i]+n+1);
    /* Check the atom name */
    if(strcasecmp(ic_atom, atom)!=0) {i++; continue;}
    /* Check the mass number, if given */
    if(mass_nr>0 && ic_mass_nr!=mass_nr) {i++; continue;}
    /* Match was found! */
    ok=1; break;
  }
  if(ok==1) return(isotope_code[i]); else return(NULL);
}
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int hlIsotopeFromHalflife(double halflife) {
  int i=0, ok=0;
  if(halflife<=0.01) return(-1);
  while(isotope_halflife[i]>0.0) {
    if( fabs(halflife/isotope_halflife[i]-1.0)<0.05 ) {ok=1; break;}
    i++;
  }
  if(ok==1) return(i);
  else return(-2.0);
}
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