Golang Rat.Quo方法代码示例

// Convert attempts to convert the constant x to a given type.
// If the attempt is successful, the result is the new constant;
// otherwise the result is invalid.
func (x Const) Convert(typ *Type) Const {
	// TODO(gri) implement this
	switch x := x.Val.(type) {
	//case bool:
	case *big.Int:
		switch Underlying(*typ) {
		case Float32, Float64:
			var z big.Rat
			z.SetInt(x)
			return Const{&z}
		case String:
			return Const{string(x.Int64())}
		case Complex64, Complex128:
			var z big.Rat
			z.SetInt(x)
			return Const{Cmplx{&z, &big.Rat{}}}
		}
	case *big.Rat:
		switch Underlying(*typ) {
		case Byte, Int, Uint, Int8, Uint8, Int16, Uint16, Int32, Uint32, Int64, Uint64:
			// Convert to an integer. Remove the fractional component.
			num, denom := x.Num(), x.Denom()
			var z big.Int
			z.Quo(num, denom)
			return Const{&z}
		}
		//case Cmplx:
		//case string:
	}
	//panic("unimplemented")
	return x
}

func binaryFloatOp(x *big.Rat, op token.Token, y *big.Rat) interface{} {
	var z big.Rat
	switch op {
	case token.ADD:
		return z.Add(x, y)
	case token.SUB:
		return z.Sub(x, y)
	case token.MUL:
		return z.Mul(x, y)
	case token.QUO:
		return z.Quo(x, y)
	case token.EQL:
		return x.Cmp(y) == 0
	case token.NEQ:
		return x.Cmp(y) != 0
	case token.LSS:
		return x.Cmp(y) < 0
	case token.LEQ:
		return x.Cmp(y) <= 0
	case token.GTR:
		return x.Cmp(y) > 0
	case token.GEQ:
		return x.Cmp(y) >= 0
	}
	panic("unreachable")
}

func renderRat(img *image.RGBA) {
	var yminR, ymaxMinR, heightR big.Rat
	yminR.SetInt64(ymin)
	ymaxMinR.SetInt64(ymax - ymin)
	heightR.SetInt64(height)

	var xminR, xmaxMinR, widthR big.Rat
	xminR.SetInt64(xmin)
	xmaxMinR.SetInt64(xmax - xmin)
	widthR.SetInt64(width)

	var y, x big.Rat
	for py := int64(0); py < height; py++ {
		// y := float64(py)/height*(ymax-ymin) + ymin
		y.SetInt64(py)
		y.Quo(&y, &heightR)
		y.Mul(&y, &ymaxMinR)
		y.Add(&y, &yminR)

		for px := int64(0); px < width; px++ {
			// x := float64(px)/width*(xmax-xmin) + xmin
			x.SetInt64(px)
			x.Quo(&x, &widthR)
			x.Mul(&x, &xmaxMinR)
			x.Add(&x, &xminR)

			c := mandelbrotRat(&x, &y)
			if c == nil {
				c = color.Black
			}
			img.Set(int(px), int(py), c)
		}
	}
}

// Total returns the total of an Usage
func (u *Usage) Total() *big.Rat {
	//return math.Min(u.Object.UnitPrice * u.BillableQuantity(), u.Object.UnitPriceCap)

	total := new(big.Rat).Mul(u.BillableQuantity(), u.Object.UnitPrice)
	total = total.Quo(total, u.Object.UnitQuantity)
	return ratMin(total, u.Object.UnitPriceCap)
}

func String(v xdr.Int64) string {
	var f, o, r big.Rat

	f.SetInt64(int64(v))
	o.SetInt64(One)
	r.Quo(&f, &o)

	return r.FloatString(7)
}

func GasPrice(bp, gl, ep *big.Int) *big.Int {
	BP := new(big.Rat).SetInt(bp)
	GL := new(big.Rat).SetInt(gl)
	EP := new(big.Rat).SetInt(ep)
	GP := new(big.Rat).Quo(BP, GL)
	GP = GP.Quo(GP, EP)

	return GP.Mul(GP, etherInWei).Num()
}

func tans(m []mTerm) *big.Rat {
	if len(m) == 1 {
		return tanEval(m[0].a, big.NewRat(m[0].n, m[0].d))
	}
	half := len(m) / 2
	a := tans(m[:half])
	b := tans(m[half:])
	r := new(big.Rat)
	return r.Quo(new(big.Rat).Add(a, b), r.Sub(one, r.Mul(a, b)))
}

// floatString returns the string representation for a
// numeric value v in normalized floating-point format.
func floatString(v exact.Value) string {
	if exact.Sign(v) == 0 {
		return "0.0"
	}
	// x != 0

	// convert |v| into a big.Rat x
	x := new(big.Rat).SetFrac(absInt(exact.Num(v)), absInt(exact.Denom(v)))

	// normalize x and determine exponent e
	// (This is not very efficient, but also not speed-critical.)
	var e int
	for x.Cmp(ten) >= 0 {
		x.Quo(x, ten)
		e++
	}
	for x.Cmp(one) < 0 {
		x.Mul(x, ten)
		e--
	}

	// TODO(gri) Values such as 1/2 are easier to read in form 0.5
	// rather than 5.0e-1. Similarly, 1.0e1 is easier to read as
	// 10.0. Fine-tune best exponent range for readability.

	s := x.FloatString(100) // good-enough precision

	// trim trailing 0's
	i := len(s)
	for i > 0 && s[i-1] == '0' {
		i--
	}
	s = s[:i]

	// add a 0 if the number ends in decimal point
	if len(s) > 0 && s[len(s)-1] == '.' {
		s += "0"
	}

	// add exponent and sign
	if e != 0 {
		s += fmt.Sprintf("e%+d", e)
	}
	if exact.Sign(v) < 0 {
		s = "-" + s
	}

	// TODO(gri) If v is a "small" fraction (i.e., numerator and denominator
	// are just a small number of decimal digits), add the exact fraction as
	// a comment. For instance: 3.3333...e-1 /* = 1/3 */

	return s
}

func sexToDec(deg, min, sec *big.Rat, dir string) *big.Rat {
	// sexagesimal (base 60) to decimal
	// https://imm.dtf.wa.gov.au/helpfiles/Latitude_Longitude_conversion_hlp.htm

	deg.Add(deg, min.Quo(min, big.NewRat(60, 1)))
	deg.Add(deg, sec.Quo(sec, big.NewRat(3600, 1)))

	// N and E are the positive directions (like on an x,y axis)
	if dir == "S" || dir == "W" {
		deg.Neg(deg)
	}

	return deg
}

func tanEval(coef int64, f *big.Rat) *big.Rat {
	if coef == 1 {
		return f
	}
	if coef < 0 {
		r := tanEval(-coef, f)
		return r.Neg(r)
	}
	ca := coef / 2
	cb := coef - ca
	a := tanEval(ca, f)
	b := tanEval(cb, f)
	r := new(big.Rat)
	return r.Quo(new(big.Rat).Add(a, b), r.Sub(one, r.Mul(a, b)))
}

func binaryCmplxOp(x cmplx, op token.Token, y cmplx) interface{} {
	a, b := x.re, x.im
	c, d := y.re, y.im
	switch op {
	case token.ADD:
		// (a+c) + i(b+d)
		var re, im big.Rat
		re.Add(a, c)
		im.Add(b, d)
		return cmplx{&re, &im}
	case token.SUB:
		// (a-c) + i(b-d)
		var re, im big.Rat
		re.Sub(a, c)
		im.Sub(b, d)
		return cmplx{&re, &im}
	case token.MUL:
		// (ac-bd) + i(bc+ad)
		var ac, bd, bc, ad big.Rat
		ac.Mul(a, c)
		bd.Mul(b, d)
		bc.Mul(b, c)
		ad.Mul(a, d)
		var re, im big.Rat
		re.Sub(&ac, &bd)
		im.Add(&bc, &ad)
		return cmplx{&re, &im}
	case token.QUO:
		// (ac+bd)/s + i(bc-ad)/s, with s = cc + dd
		var ac, bd, bc, ad, s big.Rat
		ac.Mul(a, c)
		bd.Mul(b, d)
		bc.Mul(b, c)
		ad.Mul(a, d)
		s.Add(c.Mul(c, c), d.Mul(d, d))
		var re, im big.Rat
		re.Add(&ac, &bd)
		re.Quo(&re, &s)
		im.Sub(&bc, &ad)
		im.Quo(&im, &s)
		return cmplx{&re, &im}
	case token.EQL:
		return a.Cmp(c) == 0 && b.Cmp(d) == 0
	case token.NEQ:
		return a.Cmp(c) != 0 || b.Cmp(d) != 0
	}
	panic("unreachable")
}

// ratScale multiplies x by 10**exp.
func ratScale(x *big.Rat, exp int) {
	if exp < 0 {
		x.Inv(x)
		ratScale(x, -exp)
		x.Inv(x)
		return
	}
	for exp >= 9 {
		x.Quo(x, bigRatBillion)
		exp -= 9
	}
	for exp >= 1 {
		x.Quo(x, bigRatTen)
		exp--
	}
}

func sqrtFloat(x *big.Rat) *big.Rat {
	t1 := new(big.Rat)
	t2 := new(big.Rat)
	t1.Set(x)

	// Iterate.
	// x{n} = (x{n-1}+x{0}/x{n-1}) / 2
	for i := 0; i <= 4; i++ {
		if t1.Cmp(zero) == 0 {
			return t1
		}
		t2.Quo(x, t1)
		t2.Add(t2, t1)
		t1.Mul(half, t2)
	}

	return t1
}

// ratExponent returns the power of ten that x would display in scientific notation.
func ratExponent(x *big.Rat) int {
	if x.Sign() < 0 {
		x.Neg(x)
	}
	e := 0
	invert := false
	if x.Num().Cmp(x.Denom()) < 0 {
		invert = true
		x.Inv(x)
		e++
	}
	for x.Cmp(bigRatBillion) >= 0 {
		e += 9
		x.Quo(x, bigRatBillion)
	}
	for x.Cmp(bigRatTen) > 0 {
		e++
		x.Quo(x, bigRatTen)
	}
	if invert {
		return -e
	}
	return e
}

// binaryOpConst returns the result of the constant evaluation x op y;
// both operands must be of the same "kind" (boolean, numeric, or string).
// If intDiv is true, division (op == token.QUO) is using integer division
// (and the result is guaranteed to be integer) rather than floating-point
// division. Division by zero leads to a run-time panic.
//
func binaryOpConst(x, y interface{}, op token.Token, intDiv bool) interface{} {
	x, y = matchConst(x, y)

	switch x := x.(type) {
	case bool:
		y := y.(bool)
		switch op {
		case token.LAND:
			return x && y
		case token.LOR:
			return x || y
		default:
			unreachable()
		}

	case int64:
		y := y.(int64)
		switch op {
		case token.ADD:
			// TODO(gri) can do better than this
			if is63bit(x) && is63bit(y) {
				return x + y
			}
			return normalizeIntConst(new(big.Int).Add(big.NewInt(x), big.NewInt(y)))
		case token.SUB:
			// TODO(gri) can do better than this
			if is63bit(x) && is63bit(y) {
				return x - y
			}
			return normalizeIntConst(new(big.Int).Sub(big.NewInt(x), big.NewInt(y)))
		case token.MUL:
			// TODO(gri) can do better than this
			if is32bit(x) && is32bit(y) {
				return x * y
			}
			return normalizeIntConst(new(big.Int).Mul(big.NewInt(x), big.NewInt(y)))
		case token.REM:
			return x % y
		case token.QUO:
			if intDiv {
				return x / y
			}
			return normalizeRatConst(new(big.Rat).SetFrac(big.NewInt(x), big.NewInt(y)))
		case token.AND:
			return x & y
		case token.OR:
			return x | y
		case token.XOR:
			return x ^ y
		case token.AND_NOT:
			return x &^ y
		default:
			unreachable()
		}

	case *big.Int:
		y := y.(*big.Int)
		var z big.Int
		switch op {
		case token.ADD:
			z.Add(x, y)
		case token.SUB:
			z.Sub(x, y)
		case token.MUL:
			z.Mul(x, y)
		case token.REM:
			z.Rem(x, y)
		case token.QUO:
			if intDiv {
				z.Quo(x, y)
			} else {
				return normalizeRatConst(new(big.Rat).SetFrac(x, y))
			}
		case token.AND:
			z.And(x, y)
		case token.OR:
			z.Or(x, y)
		case token.XOR:
			z.Xor(x, y)
		case token.AND_NOT:
			z.AndNot(x, y)
		default:
			unreachable()
		}
		return normalizeIntConst(&z)

	case *big.Rat:
		y := y.(*big.Rat)
		var z big.Rat
		switch op {
		case token.ADD:
			z.Add(x, y)
		case token.SUB:
			z.Sub(x, y)
//.........这里部分代码省略.........