Fix percentile when only one element (#47)

* fix percentile return error when only one element * add percentile test * update percentile Closes #46
montanaflynn · Jul 9, 2019 · dfab42c · dfab42c
1 parent 38304a2
commit dfab42c
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/percentile.go b/percentile.go
@@ -6,11 +6,15 @@ import (
 
 // Percentile finds the relative standing in a slice of floats
 func Percentile(input Float64Data, percent float64) (percentile float64, err error) {
-
-	if input.Len() == 0 {
+	length := input.Len()
+	if length == 0 {
 		return math.NaN(), EmptyInputErr
 	}
 
+	if length == 1 {
+		return input[0], nil
+	}
+
 	if percent <= 0 || percent > 100 {
 		return math.NaN(), BoundsErr
 	}

diff --git a/percentile_test.go b/percentile_test.go
@@ -10,6 +10,10 @@ func TestPercentile(t *testing.T) {
 	if m != 64.0 {
 		t.Errorf("%.1f != %.1f", m, 64.0)
 	}
+	m, _ = Percentile([]float64{43}, 90)
+	if m != 43.0 {
+		t.Errorf("%.1f != %.1f", m, 43.0)
+	}
 	m, _ = Percentile([]float64{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, 50)
 	if m != 5.0 {
 		t.Errorf("%.1f != %.1f", m, 5.0)