Esempio n. 1
0
// Estimates the Mean based on the data set
// If the data set is relatively small (< 1000 examples), then remove 1 from the total
func (ad *AnomalyDetection) estimateMean() *big.Float {

	// initialize the total to zero
	totalMean := big.NewFloat(0)

	mean := big.NewFloat(0)

	// Loop thorugh the data set
	for _, element := range ad.dataSet {

		// sum up its elements
		totalMean.Add(totalMean, &element)
		//e, _ := element.Float64()

	}

	// make a copy of the total sum and assign it to the anomaly detection object
	ad.totalSum.Copy(totalMean)

	// calculate the mean
	mean.Quo(totalMean, &ad.totalSamples)

	// assign the mean to the anomaly detection object
	ad.mean = *mean

	return mean
}
// PUT /servers/{server_id}/hardware
func (api *API) UpdateServerHardware(server_id string, hardware *Hardware) (*Server, error) {
	var vc, cpp *int
	var ram *float32
	if hardware.Vcores > 0 {
		vc = new(int)
		*vc = hardware.Vcores
	}
	if hardware.CoresPerProcessor > 0 {
		cpp = new(int)
		*cpp = hardware.CoresPerProcessor
	}
	if big.NewFloat(float64(hardware.Ram)).Cmp(big.NewFloat(0)) != 0 {
		ram = new(float32)
		*ram = hardware.Ram
	}
	req := struct {
		VCores *int     `json:"vcore,omitempty"`
		Cpp    *int     `json:"cores_per_processor,omitempty"`
		Ram    *float32 `json:"ram,omitempty"`
		Flavor string   `json:"fixed_instance_size_id,omitempty"`
	}{VCores: vc, Cpp: cpp, Ram: ram, Flavor: hardware.FixedInsSizeId}

	result := new(Server)
	url := createUrl(api, serverPathSegment, server_id, "hardware")
	err := api.Client.Put(url, &req, &result, http.StatusAccepted)
	if err != nil {
		return nil, err
	}
	result.api = api
	result.decodeRaws()
	return result, nil
}
Esempio n. 3
0
func AddBigFloat() (calculated *big.Float) {
	bigFloatStartFloat := big.NewFloat(StartFloat)
	bigFloatFactor := big.NewFloat(Factor)

	calculated = bigFloatStartFloat.Add(bigFloatStartFloat, bigFloatFactor)

	return
}
Esempio n. 4
0
func MultiplyBigFloat() (calculated *big.Float) {
	bigFloatStartFloat := big.NewFloat(StartFloat)
	bigFloatFactor := big.NewFloat(Factor)

	calculated = bigFloatStartFloat.Mul(bigFloatStartFloat, bigFloatFactor)

	return
}
Esempio n. 5
0
func BenchmarkAddBigFloatWithoutNew(b *testing.B) {
	bigFloatStartFloat := big.NewFloat(StartFloat)
	bigFloatFactor := big.NewFloat(Factor)

	for n := 0; n < b.N; n++ {
		AddBigFloatWithoutNew(bigFloatStartFloat, bigFloatFactor)
	}
}
Esempio n. 6
0
func TestSmallDataSet(t *testing.T) {

	dataSet := fakeSmallData()

	ad := NewAnomalyDetection(dataSet...)

	totalSamples, _ := ad.totalSamples.Uint64()
	if totalSamples != 20 {
		t.Fatal("Wrong number of element in the set. There are for sure 20, instead we got:", totalSamples)
	}

	totalSum, _ := ad.totalSum.Uint64()
	if totalSum != 83 {
		t.Fatal("Total sum does not add up, should be 83, we got:", totalSum)
	}

	mean, _ := ad.mean.Float64()
	if mean != 4.15 {
		t.Fatal("Mean is wrong, should be 4.15, we got:", mean)
	}

	deviation, _ := ad.deviation.Float64()
	if deviation != 1.3199999999999996 {
		t.Error("Deviation is wrong, should be 1.32 (or 1.3199999999999996), we got:", deviation)
	}

	variance, _ := ad.variance.Float64()
	if variance != 2.3325000000000005 {
		t.Error("Variance is wrong, should be 2.3325 (or 2.3325000000000005), we got:", variance)
	}

	anomaly, result := ad.EventIsAnomalous(*big.NewFloat(4.3), big.NewFloat(0.02))
	if anomaly {
		t.Errorf("5.3 should not be an anomaly !!! %f\n", result)
	}

	// stricter threshold
	anomaly, _ = ad.EventIsAnomalous(*big.NewFloat(7.3), big.NewFloat(0.1))
	if !anomaly {
		t.Error("7.3 should be an anomaly !!!")
	}

	ad.ExpandDataSet(fakeSmallData()...)
	ad.ExpandDataSet(fakeSmallData()...)

	anomaly, _ = ad.EventIsAnomalous(*big.NewFloat(5.3), big.NewFloat(0.01))
	if anomaly {
		t.Error("5.3 should not be an anomaly !!!")
	}

	// stricter threshold
	anomaly, _ = ad.EventIsAnomalous(*big.NewFloat(7.3), big.NewFloat(0.1))
	if !anomaly {
		t.Error("7.3 should be an anomaly !!!")
	}

}
Esempio n. 7
0
func BigFloatGen(r Int64F) Generator {
	return func() interface{} {
		a := float64(r())
		b := float64(r()) + 1.0
		x := big.NewFloat(a)
		y := big.NewFloat(b)
		y = y.Quo(x, y)
		return y
	}
}
func splitRangeString(start, end string, splits int) []string {
	results := []string{start}
	if start == end {
		return results
	}
	if end < start {
		tmp := start
		start = end
		end = tmp
	}

	// find longest common prefix between strings
	minLen := len(start)
	if len(end) < minLen {
		minLen = len(end)
	}
	prefix := ""
	for i := 0; i < minLen; i++ {
		if start[i] == end[i] {
			prefix = start[0 : i+1]
		} else {
			break
		}
	}

	// remove prefix from strings to split
	start = start[len(prefix):]
	end = end[len(prefix):]

	ordStart := stringToOrd(start)
	ordEnd := stringToOrd(end)

	tmp := new(big.Int)
	tmp.Sub(ordEnd, ordStart)

	stride := new(big.Float)
	stride.SetInt(tmp)
	stride.Quo(stride, big.NewFloat(float64(splits)))

	for i := 1; i <= splits; i++ {
		tmp := new(big.Float)
		tmp.Mul(stride, big.NewFloat(float64(i)))
		tmp.Add(tmp, new(big.Float).SetInt(ordStart))

		result, _ := tmp.Int(new(big.Int))

		value := prefix + ordToString(result, 0)

		if value != results[len(results)-1] {
			results = append(results, value)
		}
	}

	return results
}
Esempio n. 9
0
func TestRoot(t *testing.T) {
	x := big.NewFloat(0.12381245613960218386)
	n := 16
	res := Root(x, n)
	exp := big.NewFloat(0.8776023372475015)
	diff := new(big.Float).Sub(res, exp)
	diff = diff.Abs(diff)
	if diff.Cmp(big.NewFloat(0.00000001)) >= 0 {
		log.Fatal("Exp failed:", exp, res)
	}
}
Esempio n. 10
0
func TestPow(t *testing.T) {
	x := big.NewFloat(0.12381245613960218386)
	n := 3
	res := Pow(x, n)
	exp := big.NewFloat(0.00189798605)
	diff := new(big.Float).Sub(res, exp)
	diff = diff.Abs(diff)
	if diff.Cmp(big.NewFloat(0.00000001)) >= 0 {
		log.Fatal("Pow failed:", exp, res)
	}
}
Esempio n. 11
0
// Sqrt returns a big.Float representation of the square root of
// z. Precision is the same as the one of the argument. The function
// panics if z is negative, returns ±0 when z = ±0, and +Inf when z =
// +Inf.
func Sqrt(z *big.Float) *big.Float {

	// panic on negative z
	if z.Sign() == -1 {
		panic("Sqrt: argument is negative")
	}

	// √±0 = ±0
	if z.Sign() == 0 {
		return big.NewFloat(float64(z.Sign()))
	}

	// √+Inf  = +Inf
	if z.IsInf() {
		return big.NewFloat(math.Inf(+1))
	}

	// Compute √(a·2**b) as
	//   √(a)·2**b/2       if b is even
	//   √(2a)·2**b/2      if b > 0 is odd
	//   √(0.5a)·2**b/2    if b < 0 is odd
	//
	// The difference in the odd exponent case is due to the fact that
	// exp/2 is rounded in different directions when exp is negative.
	mant := new(big.Float)
	exp := z.MantExp(mant)
	switch exp % 2 {
	case 1:
		mant.Mul(big.NewFloat(2), mant)
	case -1:
		mant.Mul(big.NewFloat(0.5), mant)
	}

	// Solving x² - z = 0 directly requires a Quo call, but it's
	// faster for small precisions.
	//
	// Solving 1/x² - z = 0 avoids the Quo call and is much faster for
	// high precisions.
	//
	// Use sqrtDirect for prec <= 128 and sqrtInverse for prec > 128.
	var x *big.Float
	if z.Prec() <= 128 {
		x = sqrtDirect(mant)
	} else {
		x = sqrtInverse(mant)
	}

	// re-attach the exponent and return
	return x.SetMantExp(x, exp/2)

}
Esempio n. 12
0
func BenchmarkLog(b *testing.B) {
	z := big.NewFloat(2).SetPrec(1e5)
	_ = bigfloat.Log(z) // fill pi cache before benchmarking

	for _, prec := range []uint{1e2, 1e3, 1e4, 1e5} {
		z = big.NewFloat(2).SetPrec(prec)
		b.Run(fmt.Sprintf("%v", prec), func(b *testing.B) {
			b.ReportAllocs()
			for n := 0; n < b.N; n++ {
				bigfloat.Log(z)
			}
		})
	}
}
Esempio n. 13
0
func mandelbrot(z complex128) color.Color {
	const iterations = 200
	const contrast = 15

	var v complex128
	limit := new(big.Float).SetFloat64(2.0)
	for n := uint8(0); n < iterations; n++ {
		v = v*v + z
		if hypot(big.NewFloat(real(v)), big.NewFloat(imag(v))).Cmp(limit) > 2 {
			return color.Gray{255 - contrast*n}
		}
	}
	return color.Black
}
Esempio n. 14
0
File: main.go Progetto: zDpxq6/go
func mandelbrotFloat(r, i *big.Float) color.Color {
	const iterations = 200
	const contrast = 15

	a := big.NewFloat(0) //実部の初期値
	b := big.NewFloat(0) //虚部の初期値
	for n := uint8(0); n < iterations; n++ {
		a = addF(subF(mulF(a, a), mulF(b, b)), r)
		b = addF(mulF(big.NewFloat(2), mulF(a, b)), i)
		if addF(mulF(a, a), mulF(b, b)).Cmp(big.NewFloat(4)) == 1 {
			return color.Gray{255 - contrast*n}
		}
	}
	return color.Black
}
Esempio n. 15
0
func (m *meanagg) String() string {
	if m.d == 0 {
		return "NaN"
	}
	v := new(big.Float).Quo(m.v, big.NewFloat(m.d))
	return v.Text('f', -1)
}
Esempio n. 16
0
func networkGetIP(subnet *net.IPNet, host int64) net.IP {
	// Convert IP to a big int
	bigIP := big.NewInt(0)
	bigIP.SetBytes(subnet.IP.To16())

	// Deal with negative offsets
	bigHost := big.NewInt(host)
	bigCount := big.NewInt(host)
	if host < 0 {
		mask, size := subnet.Mask.Size()

		bigHosts := big.NewFloat(0)
		bigHosts.SetFloat64((math.Pow(2, float64(size-mask))))
		bigHostsInt, _ := bigHosts.Int(nil)

		bigCount.Set(bigHostsInt)
		bigCount.Add(bigCount, bigHost)
	}

	// Get the new IP int
	bigIP.Add(bigIP, bigCount)

	// Generate an IPv6
	if subnet.IP.To4() == nil {
		newIp := make(net.IP, 16)
		newIp = bigIP.Bytes()
		return newIp
	}

	// Generate an IPv4
	newIp := make(net.IP, 4)
	binary.BigEndian.PutUint32(newIp, uint32(bigIP.Int64()))
	return newIp
}
Esempio n. 17
0
func TestFixedEstimateMean(t *testing.T) {

	dataSet := fakeFixedData()

	ad := NewAnomalyDetection(dataSet...)

	mean, _ := ad.mean.Float64()
	if mean != 5052.0320320320325 {
		t.Fatal("With the current code the mean should be 5052.0320320320325, instead we got", mean)
	}

	variance, _ := ad.variance.Float64()
	//fmt.Println("Variance:", variance)

	if variance != 1536.5114864614086 {
		t.Fatal("With the current code the variance should be 1536.5114864614086, instead we got", variance)
	}

	//  threshold: 0.1%
	anomaly, result := ad.EventIsAnomalous(*big.NewFloat(5050), big.NewFloat(0.001))
	if anomaly {
		t.Errorf("5050 should NOT be an anomaly !!! %f\n", result)
	}

}
Esempio n. 18
0
func (proxy BigSequenceNumericsProxy) Extrinsically(f func()) {
	cmin := bigbase.BigComplex{proxy.RealMin, proxy.ImagMin}
	cmax := bigbase.BigComplex{proxy.RealMax, proxy.ImagMax}

	orig := []*big.Float{
		&cmin.R,
		&cmin.I,
		&cmax.R,
		&cmax.I,
	}
	copy := make([]*big.Float, len(orig))
	for i, bound := range orig {
		cp := big.NewFloat(0.0)
		cp.Copy(bound)
		copy[i] = cp
	}
	proxy.RealMin = *copy[0]
	proxy.ImagMin = *copy[1]
	proxy.RealMax = *copy[2]
	proxy.ImagMax = *copy[3]

	proxy.ClaimExtrinsics()
	f()
	proxy.RealMin = cmin.R
	proxy.ImagMin = cmin.I
	proxy.RealMax = cmax.R
	proxy.ImagMax = cmax.I

	// Should we cache this somewhere?  New object?
	proxy.RestorePicBounds()
}
Esempio n. 19
0
// compute √z using newton to solve
// t² - z = 0 for t
func sqrtDirect(z *big.Float) *big.Float {
	// f(t)/f'(t) = 0.5(t² - z)/t
	half := big.NewFloat(0.5)
	f := func(t *big.Float) *big.Float {
		x := new(big.Float).Mul(t, t) // x = t²
		x.Sub(x, z)                   // x = t² - z
		x.Mul(half, x)                // x = 0.5(t² - z)
		return x.Quo(x, t)            // return x = 0.5(t² - z)/t
	}

	// initial guess
	zf, _ := z.Float64()
	guess := big.NewFloat(math.Sqrt(zf))

	return newton(f, guess, z.Prec())
}
Esempio n. 20
0
/*红包算法
输入
红包总金额, red_mon
红包格式,   red_cou
红包最小值, red_min
红包最大值, red_max
自动返回红包
*/
func red(red_mon float64, red_cou float64, red_min float64, red_max float64) {
	fmt.Println("参数", red_mon, red_cou, red_min, red_max)
	red_evr := math.Floor(red_mon / red_cou)
	fmt.Println("平均值", red_evr)
	red_c := int(red_cou)
	red_res := make([]float64, red_c, 2*red_c)
	var re float64
	//	var re_coun string
	//在最小值和最大值之间取随机值,和平均值比较
	for i := 0; i < red_c; i++ {
		ran := xrand(red_min, red_max)
		//因为出现比平均值大的概率比较大,
		if ran > red_evr { //为了保证小红包比较多,所以比平均值大时,生成小红包
			re = red_min + xrand(red_min, red_evr)
		} else { //比平均值小的生成大红包
			re = xrand(red_evr, red_max)
		}
		//s := fmt.Sprintf("%.2f", re)
		//f, _ := strconv.ParseFloat(s, 64)
		red_res[i] = re
		red_mon -= re
	}
	//还有剩余,加到小红包
	for red_mon >= 1 {
		for i, _ := range red_res {
			if red_mon >= 1 {
				red_res[i]++
				red_mon--
			}
			//			fmt.Println(red_mon)
		}
	}

	//还有剩余,加到小红包
	for red_mon <= -1 {
		for i, _ := range red_res {
			if red_mon <= -1 {
				red_res[i]--
				red_mon++
			}
			//			fmt.Println(red_mon)
		}
	}

	for i, v := range red_res {
		f := big.NewFloat(v)
		//		red_res[i] = f
		//		re_coun += f
		fmt.Println(f)
	}

	//	red_res[0] += red_mon
	//	fmt.Println(red_res)
	//	s := fmt.Sprintf("%.2f", re_coun)
	//	fmt.Println(re_coun)
	//	s := fmt.Sprintf("%.2f", red_mon)
	//	fmt.Println(s)

}
Esempio n. 21
0
// helper function to fake fixed data
func fakeRandomData() []big.Float {

	var dataSet []big.Float

	baseInt := big.NewFloat(5000)
	// fake sample data
	for i := 0; i < 100000; i++ {
		baseInt = big.NewFloat(5000)
		if i > 200 && i < 800 {
			dataSet = append(dataSet, *baseInt.Add(baseInt, getDeviation(deviationMax)))
		} else {
			dataSet = append(dataSet, *baseInt.Add(baseInt, getDeviation(higherDeviation)))
		}
	}
	return dataSet

}
Esempio n. 22
0
// hypot for big.Float
func hypot(p, q *big.Float) *big.Float {
	// special cases
	switch {
	case p.IsInf() || q.IsInf():
		return big.NewFloat(math.Inf(1))
	}
	p = p.Abs(p)
	q = q.Abs(q)
	if p.Cmp(p) < 0 {
		p, q = q, p
	}
	if p.Cmp(big.NewFloat(0)) == 0 {
		return big.NewFloat(0)
	}
	q = q.Quo(q, p)
	return sqrt(q.Mul(q, q).Add(q, big.NewFloat(1))).Mul(q, p)
}
Esempio n. 23
0
// Implements the nth root algorithm from
// https://en.wikipedia.org/wiki/Nth_root_algorithm
// return: nth root of x within some epsilon
func Root(x *big.Float, n int64) *big.Float {
	guess := new(big.Float).Quo(x, big.NewFloat(float64(n)))
	diff := big.NewFloat(1)
	ep := big.NewFloat(0.00000001)
	abs := new(big.Float).Abs(diff)
	for abs.Cmp(ep) >= 0 {
		//fmt.Println(guess, abs)
		prev := Pow(guess, n-1)
		diff = new(big.Float).Quo(x, prev)
		diff = diff.Sub(diff, guess)
		diff = diff.Quo(diff, big.NewFloat(float64(n)))

		guess = guess.Add(guess, diff)
		abs = new(big.Float).Abs(diff)
	}
	return guess
}
Esempio n. 24
0
func TestPowSpecialValues(t *testing.T) {
	for _, f := range []struct {
		z, w float64
	}{
		{2, +0.0},
		{2, -0.0},
		{4.2, 1.0},
		{math.Inf(+1), 2.0},
	} {
		z := big.NewFloat(f.z).SetPrec(53)
		w := big.NewFloat(f.w).SetPrec(53)
		x64, acc := bigfloat.Pow(z, w).Float64()
		want := math.Pow(f.z, f.w)
		if x64 != want || acc != big.Exact {
			t.Errorf("Pow(%g, %g) =\n got %g (%s);\nwant %g (Exact)", f.z, f.w, x64, acc, want)
		}
	}
}
Esempio n. 25
0
func main() {
	const (
		xmin, ymin, xmax, ymax = -2, -2, +2, +2
		width, height          = 512, 512
	)

	img := image.NewRGBA(image.Rect(0, 0, width, height))
	for py := 0; py < height; py++ {
		y := float64(py)/height*(ymax-ymin) + ymin
		for px := 0; px < width; px++ {
			x := float64(px)/width*(xmax-xmin) + xmin
			z := complex{big.NewFloat(x), big.NewFloat(y)}
			// Image point (px, py) represents complex value z.
			img.Set(px, py, mandelbrot(z))
		}
	}
	png.Encode(os.Stdout, img) // NOTE: ignoring errors
}
Esempio n. 26
0
File: exp.go Progetto: ALTree/floats
// Exp returns a big.Float representation of exp(z). Precision is
// the same as the one of the argument. The function returns +Inf
// when z = +Inf, and 0 when z = -Inf.
func Exp(z *big.Float) *big.Float {

	// exp(0) == 1
	if z.Sign() == 0 {
		return big.NewFloat(1).SetPrec(z.Prec())
	}

	// Exp(+Inf) = +Inf
	if z.IsInf() && z.Sign() > 0 {
		return big.NewFloat(math.Inf(+1)).SetPrec(z.Prec())
	}

	// Exp(-Inf) = 0
	if z.IsInf() && z.Sign() < 0 {
		return big.NewFloat(0).SetPrec(z.Prec())
	}

	guess := new(big.Float)

	// try to get initial estimate using IEEE-754 math
	zf, _ := z.Float64()
	if zfs := math.Exp(zf); zfs == math.Inf(+1) || zfs == 0 {
		// too big or too small for IEEE-754 math,
		// perform argument reduction using
		//     e^{2z} = (e^z)²
		halfZ := new(big.Float).Mul(z, big.NewFloat(0.5))
		halfExp := Exp(halfZ.SetPrec(z.Prec() + 64))
		return new(big.Float).Mul(halfExp, halfExp).SetPrec(z.Prec())
	} else {
		// we got a nice IEEE-754 estimate
		guess.SetFloat64(zfs)
	}

	// f(t)/f'(t) = t*(log(t) - z)
	f := func(t *big.Float) *big.Float {
		x := new(big.Float)
		x.Sub(Log(t), z)
		return x.Mul(x, t)
	}

	x := newton(f, guess, z.Prec())

	return x
}
Esempio n. 27
0
// return: x^y
func Pow(x *big.Float, n int64) *big.Float {
	res := new(big.Float).Copy(x)
	if n < 0 {
		res = res.Quo(big.NewFloat(1), res)
		n = -n
	} else if n == 0 {
		return big.NewFloat(1)
	}
	y := big.NewFloat(1)
	for i := n; i > 1; {
		if i%2 == 0 {
			i /= 2
		} else {
			y = y.Mul(res, y)
			i = (i - 1) / 2
		}
		res = res.Mul(res, res)
	}
	return res.Mul(res, y)
}
Esempio n. 28
0
// Estimates the Variance based on the data set
// If the data set is relatively small (< 1000 examples), then remove 1 from the total
func (ad *AnomalyDetection) estimateVariance() *big.Float {

	// this means that the mean was never calculated before, therefore do it now
	// the means is needed for the cimputation of the deviation
	if ad.mean.Cmp(zero) == 0 {
		ad.estimateMean()
	}

	// initialize the total to zero
	totalVariance := big.NewFloat(0)
	totalDeviation := big.NewFloat(0)

	var deviation big.Float
	var deviationCopy big.Float

	var singleVariance big.Float

	// Loop while a is smaller than 1e100.
	for _, element := range ad.dataSet {
		// first calculate the deviation for each element, by subtracting the mean, take the absolute value
		deviation.Sub(&element, &ad.mean).Abs(&deviation)

		// add it to the total
		totalDeviation.Add(totalDeviation, &deviation)

		// calculate the variance by squaring it
		singleVariance = *deviationCopy.Mul(&deviation, &deviation) // ^2

		// the calculate the variance
		totalVariance.Add(totalVariance, &singleVariance)
	}

	// calculate the variance
	// assign the variance to the anomaly detection object
	ad.variance = *totalVariance.Quo(totalVariance, &ad.totalSamples)

	// calculate the deviation
	ad.deviation = *totalDeviation.Quo(totalDeviation, &ad.totalSamples)

	return &ad.variance
}
Esempio n. 29
0
File: pow.go Progetto: ALTree/floats
// Pow returns a big.Float representation of z**w. Precision is the same as the one
// of the first argument. The function panics when z is negative.
func Pow(z *big.Float, w *big.Float) *big.Float {

	if z.Sign() < 0 {
		panic("Pow: negative base")
	}

	// Pow(z, 0) = 1.0
	if w.Sign() == 0 {
		return big.NewFloat(1).SetPrec(z.Prec())
	}

	// Pow(z, 1) = z
	// Pow(+Inf, n) = +Inf
	if w.Cmp(big.NewFloat(1)) == 0 || z.IsInf() {
		return new(big.Float).Copy(z)
	}

	// Pow(z, -w) = 1 / Pow(z, w)
	if w.Sign() < 0 {
		x := new(big.Float)
		zExt := new(big.Float).Copy(z).SetPrec(z.Prec() + 64)
		wNeg := new(big.Float).Neg(w)
		return x.Quo(big.NewFloat(1), Pow(zExt, wNeg)).SetPrec(z.Prec())
	}

	// w integer fast path
	if w.IsInt() {
		wi, _ := w.Int64()
		return powInt(z, int(wi))
	}

	// compute w**z as exp(z log(w))
	x := new(big.Float).SetPrec(z.Prec() + 64)
	logZ := Log(new(big.Float).Copy(z).SetPrec(z.Prec() + 64))
	x.Mul(w, logZ)
	x = Exp(x)
	return x.SetPrec(z.Prec())

}
func TestFormatNumberBigFloat(t *testing.T) {
	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(123456789.213123), 3, ",", "."), "123,456,789.213")
	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-12345.123123), 5, ",", "."), "-12,345.12312")
	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-1234.123123), 5, ",", "."), "-1,234.12312")
	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-123.123123), 5, ",", "."), "-123.12312")
	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-12.123123), 5, ",", "."), "-12.12312")
	AssertEqual(t, FormatNumberBigFloat(big.NewFloat(-1.123123), 5, ",", "."), "-1.12312")
}