Upstream montanaflynn/stats state of the touched files before e61f9a13db

quartile.go

@@ -32,20 +32,10 @@ func Quartile(input Float64Data) (Quartiles, error) {
 		c2 = c1 + 1
 	}
 
-	// Empty halves make Median return ErrEmptyInput; propagate it instead of
-	// returning NaN quartiles.
-	Q1, err := Median(copy[:c1])
-	if err != nil {
-		return Quartiles{}, err
-	}
-	Q2, err := Median(copy)
-	if err != nil {
-		return Quartiles{}, err
-	}
-	Q3, err := Median(copy[c2:])
-	if err != nil {
-		return Quartiles{}, err
-	}
+	// Find the Medians with the cutoff points
+	Q1, _ := Median(copy[:c1])
+	Q2, _ := Median(copy)
+	Q3, _ := Median(copy[c2:])
 
 	return Quartiles{Q1, Q2, Q3}, nil
 
@@ -56,10 +46,7 @@ func InterQuartileRange(input Float64Data) (float64, error) {
 	if input.Len() == 0 {
 		return math.NaN(), EmptyInputErr
 	}
-	qs, err := Quartile(input)
-	if err != nil {
-		return math.NaN(), err
-	}
+	qs, _ := Quartile(input)
 	iqr := qs.Q3 - qs.Q1
 	return iqr, nil
 }
@@ -69,10 +56,7 @@ func Midhinge(input Float64Data) (float64, error) {
 	if input.Len() == 0 {
 		return math.NaN(), EmptyInputErr
 	}
-	qs, err := Quartile(input)
-	if err != nil {
-		return math.NaN(), err
-	}
+	qs, _ := Quartile(input)
 	mh := (qs.Q1 + qs.Q3) / 2
 	return mh, nil
 }
@@ -84,10 +68,7 @@ func Trimean(input Float64Data) (float64, error) {
 	}
 
 	c := sortedCopy(input)
-	q, err := Quartile(c)
-	if err != nil {
-		return math.NaN(), err
-	}
+	q, _ := Quartile(c)
 
 	return (q.Q1 + (q.Q2 * 2) + q.Q3) / 4, nil
 }

quartile_test.go

@@ -41,18 +41,6 @@ func TestQuartile(t *testing.T) {
 	}
 }
 
-func TestQuartileSingleElement(t *testing.T) {
-	// A single element has no halves, so Quartile must error rather than
-	// return NaN with a nil error.
-	quartiles, err := stats.Quartile([]float64{1})
-	if err == nil {
-		t.Errorf("Single element slice should have returned an error")
-	}
-	if quartiles != (stats.Quartiles{}) {
-		t.Errorf("Errored result should be the zero Quartiles value, got %+v", quartiles)
-	}
-}
-
 func TestInterQuartileRange(t *testing.T) {
 	s1 := []float64{102, 104, 105, 107, 108, 109, 110, 112, 115, 116, 118}
 	iqr, _ := stats.InterQuartileRange(s1)
@@ -65,11 +53,6 @@ func TestInterQuartileRange(t *testing.T) {
 	if err == nil {
 		t.Errorf("Empty slice should have returned an error")
 	}
-
-	_, err = stats.InterQuartileRange([]float64{1})
-	if err == nil {
-		t.Errorf("Single element slice should have returned an error")
-	}
 }
 
 func TestMidhinge(t *testing.T) {
@@ -84,11 +67,6 @@ func TestMidhinge(t *testing.T) {
 	if err == nil {
 		t.Errorf("Empty slice should have returned an error")
 	}
-
-	_, err = stats.Midhinge([]float64{1})
-	if err == nil {
-		t.Errorf("Single element slice should have returned an error")
-	}
 }
 
 func TestTrimean(t *testing.T) {
@@ -103,9 +81,4 @@ func TestTrimean(t *testing.T) {
 	if err == nil {
 		t.Errorf("Empty slice should have returned an error")
 	}
-
-	_, err = stats.Trimean([]float64{1})
-	if err == nil {
-		t.Errorf("Single element slice should have returned an error")
-	}
 }