Adding upstream version 2.1.2.

Signed-off-by: Daniel Baumann <daniel@debian.org>

ema_series_test.go

@@ -0,0 +1,105 @@
+package chart
+
+import (
+	"testing"
+
+	"github.com/wcharczuk/go-chart/v2/testutil"
+)
+
+var (
+	emaXValues = LinearRange(1.0, 50.0)
+	emaYValues = []float64{
+		1, 2, 3, 4, 5, 4, 3, 2,
+		1, 2, 3, 4, 5, 4, 3, 2,
+		1, 2, 3, 4, 5, 4, 3, 2,
+		1, 2, 3, 4, 5, 4, 3, 2,
+		1, 2, 3, 4, 5, 4, 3, 2,
+		1, 2, 3, 4, 5, 4, 3, 2,
+		1, 2,
+	}
+	emaExpected = []float64{
+		1,
+		1.074074074,
+		1.216735254,
+		1.422903013,
+		1.68787316,
+		1.859141815,
+		1.943649828,
+		1.947823915,
+		1.877614736,
+		1.886680311,
+		1.969148437,
+		2.119581886,
+		2.33294619,
+		2.456431658,
+		2.496695979,
+		2.459903685,
+		2.351762671,
+		2.325706177,
+		2.375653867,
+		2.495975803,
+		2.681459077,
+		2.779128775,
+		2.795489607,
+		2.73656445,
+		2.607930047,
+		2.562898191,
+		2.595276103,
+		2.699329725,
+		2.869749746,
+		2.953471987,
+		2.956918506,
+		2.886035654,
+		2.746329309,
+		2.691045657,
+		2.713931163,
+		2.809195522,
+		2.971477335,
+		3.047664199,
+		3.044133518,
+		2.966790294,
+		2.821102124,
+		2.760279745,
+		2.778036801,
+		2.868552593,
+		3.026437586,
+		3.098553321,
+		3.091253075,
+		3.010419514,
+		2.86149955,
+		2.797684768,
+	}
+	emaDelta = 0.0001
+)
+
+func TestEMASeries(t *testing.T) {
+	// replaced new assertions helper
+
+	mockSeries := mockValuesProvider{
+		emaXValues,
+		emaYValues,
+	}
+	testutil.AssertEqual(t, 50, mockSeries.Len())
+
+	ema := &EMASeries{
+		InnerSeries: mockSeries,
+		Period:      26,
+	}
+
+	sig := ema.GetSigma()
+	testutil.AssertEqual(t, 2.0/(26.0+1), sig)
+
+	var yvalues []float64
+	for x := 0; x < ema.Len(); x++ {
+		_, y := ema.GetValues(x)
+		yvalues = append(yvalues, y)
+	}
+
+	for index, yv := range yvalues {
+		testutil.AssertInDelta(t, yv, emaExpected[index], emaDelta)
+	}
+
+	lvx, lvy := ema.GetLastValues()
+	testutil.AssertEqual(t, 50.0, lvx)
+	testutil.AssertInDelta(t, lvy, emaExpected[49], emaDelta)
+}