Adding dep files and dependencies.

vendor/github.com/montanaflynn/stats/deviation.go

@@ -0,0 +1,57 @@
+package stats
+
+import "math"
+
+// MedianAbsoluteDeviation finds the median of the absolute deviations from the dataset median
+func MedianAbsoluteDeviation(input Float64Data) (mad float64, err error) {
+	return MedianAbsoluteDeviationPopulation(input)
+}
+
+// MedianAbsoluteDeviationPopulation finds the median of the absolute deviations from the population median
+func MedianAbsoluteDeviationPopulation(input Float64Data) (mad float64, err error) {
+	if input.Len() == 0 {
+		return math.NaN(), EmptyInput
+	}
+
+	i := copyslice(input)
+	m, _ := Median(i)
+
+	for key, value := range i {
+		i[key] = math.Abs(value - m)
+	}
+
+	return Median(i)
+}
+
+// StandardDeviation the amount of variation in the dataset
+func StandardDeviation(input Float64Data) (sdev float64, err error) {
+	return StandardDeviationPopulation(input)
+}
+
+// StandardDeviationPopulation finds the amount of variation from the population
+func StandardDeviationPopulation(input Float64Data) (sdev float64, err error) {
+
+	if input.Len() == 0 {
+		return math.NaN(), EmptyInput
+	}
+
+	// Get the population variance
+	vp, _ := PopulationVariance(input)
+
+	// Return the population standard deviation
+	return math.Pow(vp, 0.5), nil
+}
+
+// StandardDeviationSample finds the amount of variation from a sample
+func StandardDeviationSample(input Float64Data) (sdev float64, err error) {
+
+	if input.Len() == 0 {
+		return math.NaN(), EmptyInput
+	}
+
+	// Get the sample variance
+	vs, _ := SampleVariance(input)
+
+	// Return the sample standard deviation
+	return math.Pow(vs, 0.5), nil
+}