feat: add new functions to mathutil package

mathutil/mathutil.go

@@ -91,6 +91,34 @@ func TruncRound(x float64, n int) float64 {
 	return res
 }
 
+// FloorToFloat round down to n decimal places.
+func FloorToFloat(x float64, n int) float64 {
+	return math.Floor(x*math.Pow(10, float64(n))) / math.Pow(10.0, float64(n))
+}
+
+// FloorToString round down to n decimal places.
+func FloorToString(x float64, n int) string {
+	tmp := math.Pow(10.0, float64(n))
+	x *= tmp
+	x = math.Floor(x)
+	res := strconv.FormatFloat(x/tmp, 'f', n, 64)
+	return res
+}
+
+// CeilToFloat round up to n decimal places.
+func CeilToFloat(x float64, n int) float64 {
+	pow10n := math.Pow10(n)
+	return math.Ceil(x*pow10n) / pow10n
+}
+
+// CeilToString round up to n decimal places.
+func CeilToString(x float64, n int) string {
+	multiplier := math.Pow(10, float64(n))
+	rounded := math.Ceil(x*multiplier) / multiplier
+
+	return fmt.Sprintf("%.*f", n, rounded)
+}
+
 // AngleToRadian converts angle value to radian value.
 func AngleToRadian(angle float64) float64 {
 	radian := angle * (math.Pi / 180)

mathutil/mathutil_test.go

@@ -180,3 +180,46 @@ func TestLog(t *testing.T) {
 	assert.EqualValues(3, TruncRound(Log(27, 3), 0))
 	assert.EqualValues(2.32, TruncRound(Log(5, 2), 2))
 }
+
+func TestFloorToFloat(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestFloorToFloat")
+
+	assert.Equal(3.14, FloorToFloat(3.14159, 2))
+	assert.Equal(3.141, FloorToFloat(3.14159, 3))
+	assert.Equal(5.0, FloorToFloat(5, 4))
+	assert.Equal(2.0, FloorToFloat(9/4, 2))
+}
+
+func TestFloorToString(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestFloorToString")
+
+	assert.Equal("3.14", FloorToString(3.14159, 2))
+	assert.Equal("3.141", FloorToString(3.14159, 3))
+	assert.Equal("5.0000", FloorToString(5, 4))
+}
+
+func TestCeilToFloat(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestCeilToFloat")
+
+	assert.Equal(3.15, CeilToFloat(3.14159, 2))
+	assert.Equal(3.142, CeilToFloat(3.14159, 3))
+	assert.Equal(5.0, CeilToFloat(5, 4))
+	assert.Equal(0.15, CeilToFloat(float64(1)/float64(7), 2))
+}
+
+func TestCeilToString(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestCeilToFloat")
+
+	assert.Equal("3.15", CeilToString(3.14159, 2))
+	assert.Equal("3.142", CeilToString(3.14159, 3))
+	assert.Equal("5.0000", CeilToString(5, 4))
+	assert.Equal("0.15", CeilToString(float64(1)/float64(7), 2))
+}