char float_gamma( floatnum x, int digits) { signed char sign; char result; if (!chckmathparam(x, digits)) return 0; sign = float_getsign(x); if (float_isinteger(x)) { if (sign <= 0) return _seterror(x, ZeroDivide); result = _gammaint(x, digits); } else if (float_getlength(x) - float_getexponent(x) == 2 && float_getdigit(x, float_getlength(x) - 1) == 5) result = _gamma0_5(x, digits); else result = _gamma(x, digits); if (!result) { if (sign < 0) float_seterror(Underflow); else float_seterror(Overflow); float_setnan(x); } return result; }
static char _cvtlogic( t_longint* lx, cfloatnum x) { if (float_isnan(x)) { float_seterror(NoOperand); return 0; } if (_floatnum2logic(lx, x)) return 1; float_seterror(OutOfLogicRange); return 0; }
char float_raise( floatnum power, cfloatnum base, cfloatnum exponent, int digits) { signed char sgn; if (float_isnan(exponent) || float_isnan(base)) return _seterror(power, NoOperand); if (digits <= 0 || digits > MATHPRECISION) return _seterror(power, InvalidPrecision); if (float_iszero(base)) { switch(float_getsign(exponent)) { case 0: return _seterror(power, OutOfDomain); case -1: return _seterror(power, ZeroDivide); } return _setzero(power); } sgn = float_getsign(base); if (sgn < 0) { if (!float_isinteger(exponent)) return _seterror(power, OutOfDomain); if ((float_getdigit(exponent, float_getexponent(exponent)) & 1) == 0) sgn = 1; } float_copy(power, base, digits+1); float_abs(power); if (!_raise(power, exponent, digits)) { float_seterror(Overflow); if (float_getexponent(base) * float_getsign(exponent) < 0) float_seterror(Underflow); return _setnan(power); } float_setsign(power, sgn); return 1; }
Error pack2floatnum( floatnum x, p_number_desc n) { floatstruct tmp; int digits; int saveerr; int saverange; Error result; signed char base; if ((result = _pack2int(x, &n->intpart)) != Success) return result; if (float_isnan(x)) return Success; saveerr = float_geterror(); saverange = float_setrange(MAXEXP); float_create(&tmp); float_move(&tmp, x); float_setzero(x); digits = DECPRECISION - float_getexponent(&tmp); if (digits <= 0 || (result = _pack2frac(x, &n->fracpart, digits)) == Success) float_add(x, x, &tmp, DECPRECISION); if (result != Success) return result; if ((!float_getlength(x)) == 0) /* no zero, no NaN? */ { base = n->prefix.base; float_setinteger(&tmp, base); if (n->exp >= 0) { _raiseposi_(&tmp, n->exp, DECPRECISION + 2); float_mul(x, x, &tmp, DECPRECISION + 2); } else { _raiseposi_(&tmp, -n->exp, DECPRECISION + 2); float_div(x, x, &tmp, DECPRECISION + 2); } } float_free(&tmp); float_setsign(x, n->prefix.sign == IO_SIGN_COMPLEMENT? -1 : n->prefix.sign); float_geterror(); float_seterror(saveerr); float_setrange(saverange); if (!float_isvalidexp(float_getexponent(x))) float_setnan(x); return float_isnan(x)? IOExpOverflow : Success; }
static char _pochhammer_g( floatnum x, cfloatnum n, int digits) { /* this generalizes the rising Pochhammer symbol using the formula pochhammer(x,n) = Gamma(x+1)/Gamma(x-n+1) */ floatstruct tmp, factor1, factor2; int inf1, inf2; char result; float_create(&tmp); float_create(&factor1); float_create(&factor2); inf2 = 0; float_add(&tmp, x, n, digits+1); result = _lngamma_prim(x, &factor1, &inf1, digits) && _lngamma_prim(&tmp, &factor2, &inf2, digits) && (inf2 -= inf1) <= 0; if (inf2 > 0) float_seterror(ZeroDivide); if (result && inf2 < 0) float_setzero(x); if (result && inf2 == 0) result = float_div(&factor1, &factor1, &factor2, digits+1) && float_sub(x, &tmp, x, digits+1) && _exp(x, digits) && float_mul(x, x, &factor1, digits+1); float_free(&tmp); float_free(&factor2); float_free(&factor1); if (!result) float_setnan(x); return result; }