Adding dep files and dependencies.

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

@@ -0,0 +1,80 @@
+package stats
+
+import "math"
+
+// Percentile finds the relative standing in a slice of floats
+func Percentile(input Float64Data, percent float64) (percentile float64, err error) {
+
+	if input.Len() == 0 {
+		return math.NaN(), EmptyInput
+	}
+
+	if percent <= 0 || percent > 100 {
+		return math.NaN(), BoundsErr
+	}
+
+	// Start by sorting a copy of the slice
+	c := sortedCopy(input)
+
+	// Multiply percent by length of input
+	index := (percent / 100) * float64(len(c))
+
+	// Check if the index is a whole number
+	if index == float64(int64(index)) {
+
+		// Convert float to int
+		i := int(index)
+
+		// Find the value at the index
+		percentile = c[i-1]
+
+	} else if index > 1 {
+
+		// Convert float to int via truncation
+		i := int(index)
+
+		// Find the average of the index and following values
+		percentile, _ = Mean(Float64Data{c[i-1], c[i]})
+
+	} else {
+		return math.NaN(), BoundsErr
+	}
+
+	return percentile, nil
+
+}
+
+// PercentileNearestRank finds the relative standing in a slice of floats using the Nearest Rank method
+func PercentileNearestRank(input Float64Data, percent float64) (percentile float64, err error) {
+
+	// Find the length of items in the slice
+	il := input.Len()
+
+	// Return an error for empty slices
+	if il == 0 {
+		return math.NaN(), EmptyInput
+	}
+
+	// Return error for less than 0 or greater than 100 percentages
+	if percent < 0 || percent > 100 {
+		return math.NaN(), BoundsErr
+	}
+
+	// Start by sorting a copy of the slice
+	c := sortedCopy(input)
+
+	// Return the last item
+	if percent == 100.0 {
+		return c[il-1], nil
+	}
+
+	// Find ordinal ranking
+	or := int(math.Ceil(float64(il) * percent / 100))
+
+	// Return the item that is in the place of the ordinal rank
+	if or == 0 {
+		return c[0], nil
+	}
+	return c[or-1], nil
+
+}