/* * ecvt converts to decimal * the number of digits is specified by ndigit * decpt is set to the position of the decimal point * sign is set to 0 for positive, 1 for negative */ char *cvt(); #define NDIG 80 char* ecvt(arg, ndigits, decpt, sign) double arg; int ndigits, *decpt, *sign; { return(cvt(arg, ndigits, decpt, sign, 1)); } char* fcvt(arg, ndigits, decpt, sign) double arg; int ndigits, *decpt, *sign; { return(cvt(arg, ndigits, decpt, sign, 0)); } static char* cvt(arg, ndigits, decpt, sign, eflag) double arg; int ndigits, *decpt, *sign; { register int r2; double fi, fj; register char *p, *p1; static char buf[NDIG]; double modf(); if (ndigits<0) ndigits = 0; if (ndigits>=NDIG-1) ndigits = NDIG-2; r2 = 0; *sign = 0; p = &buf[0]; if (arg<0) { *sign = 1; arg = -arg; } arg = modf(arg, &fi); p1 = &buf[NDIG]; /* * Do integer part */ if (fi != 0) { p1 = &buf[NDIG]; while (fi != 0) { fj = modf(fi/10, &fi); *--p1 = (int)((fj+.03)*10) + '0'; r2++; } while (p1 < &buf[NDIG]) *p++ = *p1++; } else if (arg > 0) { while ((fj = arg*10) < 1) { arg = fj; r2--; } } p1 = &buf[ndigits]; if (eflag==0) p1 += r2; *decpt = r2; if (p1 < &buf[0]) { buf[0] = '\0'; return(buf); } while (p<=p1 && p<&buf[NDIG]) { arg *= 10; arg = modf(arg, &fj); *p++ = (int)fj + '0'; } if (p1 >= &buf[NDIG]) { buf[NDIG-1] = '\0'; return(buf); } p = p1; *p1 += 5; while (*p1 > '9') { *p1 = '0'; if (p1>buf) ++*--p1; else { *p1 = '1'; (*decpt)++; if (eflag==0) { if (p>buf) *p = '0'; p++; } } } *p = '\0'; return(buf); }