stats.go

package indicators

import "math"

type mfloat []float64

// Avg returns 'data' average.
func Avg(data []float64) float64 {

	return Sum(data) / float64(len(data))
}

// Sum returns the sum of all elements of 'data'.
func Sum(data []float64) float64 {

	var sum float64

	for _, x := range data {
		sum += x
	}

	return sum
}

// Std returns standard deviation of a slice.
func Std(slice []float64) float64 {

	var result []float64

	mean := Avg(slice)

	for i := 0; i < len(slice); i++ {
		result = append(result, math.Pow(slice[i]-mean, 2))
	}

	return math.Sqrt(Sum(result) / float64(len(result)))
}

// AddToAll adds a value to all slice elements.
func (slice mfloat) AddToAll(val float64) []float64 {

	var addedSlice []float64

	for i := 0; i < len(slice); i++ {
		addedSlice = append(addedSlice, slice[i] + val)
	}

	return addedSlice
}

// SubSlices subtracts two slices.
func SubSlices(slice1, slice2 []float64) []float64 {

	var result []float64

	for i := 0; i < len(slice1); i++ {
		result = append(result, slice1[i]-slice2[i])
	}

	return result	
}

// AddSlices adds two slices.
func AddSlices(slice1, slice2 []float64) []float64 {

	var result []float64

	for i := 0; i < len(slice1); i++ {
		result = append(result, slice1[i]+slice2[i])
	}

	return result	
}

// DivSlice divides a slice by a float.
func DivSlice(slice []float64, n float64) []float64 {

	var result []float64

	for i := 0; i < len(slice); i++ {
		result = append(result, slice[i]/n)
	}

	return result
}