Upstream montanaflynn/stats state of the touched files before a9577323b0

quartile.go

@@ -10,9 +10,6 @@ type Quartiles struct {
 }
 
 // Quartile returns the three quartile points from a slice of data
-//
-// A single value is its own lower hinge, median and upper hinge, so all
-// three quartiles are that value.
 func Quartile(input Float64Data) (Quartiles, error) {
 
 	il := input.Len()
@@ -20,14 +17,6 @@ func Quartile(input Float64Data) (Quartiles, error) {
 		return Quartiles{}, EmptyInputErr
 	}
 
-	// One value is its own quartiles, which also matches what Percentile
-	// returns for that value at any percent. The general path below cannot
-	// produce it: the cutoffs would leave both halves empty and the two
-	// hinges would come back as NaN.
-	if il == 1 {
-		return Quartiles{input[0], input[0], input[0]}, nil
-	}
-
 	// Start by sorting a copy of the slice
 	copy := sortedCopy(input)
 
@@ -43,8 +32,7 @@ func Quartile(input Float64Data) (Quartiles, error) {
 		c2 = c1 + 1
 	}
 
-	// Find the Medians with the cutoff points. Both halves hold at least
-	// one value for every length above one, so Median cannot fail here.
+	// Find the Medians with the cutoff points
 	Q1, _ := Median(copy[:c1])
 	Q2, _ := Median(copy)
 	Q3, _ := Median(copy[c2:])

quartile_test.go

@@ -41,47 +41,6 @@ func TestQuartile(t *testing.T) {
 	}
 }
 
-func TestQuartile_SingleValue(t *testing.T) {
-	quartiles, err := stats.Quartile([]float64{43})
-	if err != nil {
-		t.Errorf("Should not have returned an error; got %v", err)
-	}
-	if quartiles.Q1 != 43 {
-		t.Errorf("Q1 %v != 43", quartiles.Q1)
-	}
-	if quartiles.Q2 != 43 {
-		t.Errorf("Q2 %v != 43", quartiles.Q2)
-	}
-	if quartiles.Q3 != 43 {
-		t.Errorf("Q3 %v != 43", quartiles.Q3)
-	}
-
-	// The quartiles of one value agree with Percentile on the same value.
-	for _, percent := range []float64{25, 50, 75} {
-		value, err := stats.Percentile([]float64{43}, percent)
-		if err != nil || value != 43 {
-			t.Errorf("Percentile %v on one value: got %v (err %v)", percent, value, err)
-		}
-	}
-}
-
-func TestQuartile_SingleValueDependents(t *testing.T) {
-	iqr, err := stats.InterQuartileRange([]float64{43})
-	if err != nil || iqr != 0 {
-		t.Errorf("IQR of one value: got %v (err %v), want 0", iqr, err)
-	}
-
-	mh, err := stats.Midhinge([]float64{43})
-	if err != nil || mh != 43 {
-		t.Errorf("Midhinge of one value: got %v (err %v), want 43", mh, err)
-	}
-
-	tr, err := stats.Trimean([]float64{43})
-	if err != nil || tr != 43 {
-		t.Errorf("Trimean of one value: got %v (err %v), want 43", tr, err)
-	}
-}
-
 func TestInterQuartileRange(t *testing.T) {
 	s1 := []float64{102, 104, 105, 107, 108, 109, 110, 112, 115, 116, 118}
 	iqr, _ := stats.InterQuartileRange(s1)