TEMA indicator is added.

README.md

@@ -45,7 +45,7 @@ The following list of indicators are currently supported by this package:
 - Rolling Moving Average (RMA)
 - [Simple Moving Average (SMA)](trend/README.md#type-sma)
 - [Since Change](helper/README.md#func-since)
-- Triple Exponential Moving Average (TEMA)
+- [Triple Exponential Moving Average (TEMA)](trend/README.md#type-tema)
 - Triangular Moving Average (TRIMA)
 - Triple Exponential Average (TRIX)
 - Typical Price

trend/README.md

@@ -65,6 +65,10 @@ The information provided on this project is strictly for informational purposes
 - [type Sma](<#Sma>)
   - [func NewSma\[T helper.Number\]\(\) \*Sma\[T\]](<#NewSma>)
   - [func \(s \*Sma\[T\]\) Compute\(c \<\-chan T\) \<\-chan T](<#Sma[T].Compute>)
+- [type Tema](<#Tema>)
+  - [func NewTema\[T helper.Number\]\(\) \*Tema\[T\]](<#NewTema>)
+  - [func \(t \*Tema\[T\]\) Compute\(c \<\-chan T\) \<\-chan T](<#Tema[T].Compute>)
+  - [func \(t \*Tema\[T\]\) IdlePeriod\(\) int](<#Tema[T].IdlePeriod>)
 
 
 ## Constants
@@ -691,4 +695,51 @@ func (s *Sma[T]) Compute(c <-chan T) <-chan T
 
 Compute function takes a channel of numbers and computes the SMA over the specified period.
 
+<a name="Tema"></a>
+## type [Tema](<https://github.com/cinar/indicator/blob/v2/trend/tema.go#L18-L22>)
+
+Tema represents the configuration parameters for calculating the Triple Exponential Moving Average \(TEMA\).
+
+```
+TEMA = (3 * EMA1) - (3 * EMA2) + EMA3
+EMA1 = EMA(values)
+EMA2 = EMA(EMA1)
+EMA3 = EMA(EMA2)
+```
+
+```go
+type Tema[T helper.Number] struct {
+    Ema1 *Ema[T]
+    Ema2 *Ema[T]
+    Ema3 *Ema[T]
+}
+```
+
+<a name="NewTema"></a>
+### func [NewTema](<https://github.com/cinar/indicator/blob/v2/trend/tema.go#L26>)
+
+```go
+func NewTema[T helper.Number]() *Tema[T]
+```
+
+NewTema function initializes a new TEMA instance with the default parameters.
+
+<a name="Tema[T].Compute"></a>
+### func \(\*Tema\[T\]\) [Compute](<https://github.com/cinar/indicator/blob/v2/trend/tema.go#L36>)
+
+```go
+func (t *Tema[T]) Compute(c <-chan T) <-chan T
+```
+
+Compute function takes a channel of numbers and computes the TEMA and the signal line.
+
+<a name="Tema[T].IdlePeriod"></a>
+### func \(\*Tema\[T\]\) [IdlePeriod](<https://github.com/cinar/indicator/blob/v2/trend/tema.go#L65>)
+
+```go
+func (t *Tema[T]) IdlePeriod() int
+```
+
+IdlePeriod is the initial period that TEMA won't yield any results.
+
 Generated by [gomarkdoc](<https://github.com/princjef/gomarkdoc>)

trend/tema.go

@@ -0,0 +1,67 @@
+// Copyright (c) 2021-2023 Onur Cinar.
+// The source code is provided under GNU AGPLv3 License.
+// https://github.com/cinar/indicator
+
+package trend
+
+import (
+	"github.com/cinar/indicator/helper"
+)
+
+// Tema represents the configuration parameters for calculating the
+// Triple Exponential Moving Average (TEMA).
+//
+//	TEMA = (3 * EMA1) - (3 * EMA2) + EMA3
+//	EMA1 = EMA(values)
+//	EMA2 = EMA(EMA1)
+//	EMA3 = EMA(EMA2)
+type Tema[T helper.Number] struct {
+	Ema1 *Ema[T]
+	Ema2 *Ema[T]
+	Ema3 *Ema[T]
+}
+
+// NewTema function initializes a new TEMA instance
+// with the default parameters.
+func NewTema[T helper.Number]() *Tema[T] {
+	return &Tema[T]{
+		Ema1: NewEma[T](),
+		Ema2: NewEma[T](),
+		Ema3: NewEma[T](),
+	}
+}
+
+// Compute function takes a channel of numbers and computes the TEMA
+// and the signal line.
+func (t *Tema[T]) Compute(c <-chan T) <-chan T {
+	ema1 := helper.Duplicate(
+		t.Ema1.Compute(c),
+		2,
+	)
+
+	ema2 := helper.Duplicate(
+		t.Ema2.Compute(ema1[0]),
+		2,
+	)
+
+	ema1[1] = helper.Skip(ema1[1], t.Ema2.Period-1)
+
+	ema3 := t.Ema3.Compute(ema2[0])
+	ema1[1] = helper.Skip(ema1[1], t.Ema3.Period-1)
+	ema2[1] = helper.Skip(ema2[1], t.Ema3.Period-1)
+
+	tema := helper.Add(
+		helper.Subtract(
+			helper.MultiplyBy(ema1[1], 3),
+			helper.MultiplyBy(ema2[1], 3),
+		),
+		ema3,
+	)
+
+	return tema
+}
+
+// IdlePeriod is the initial period that TEMA won't yield any results.
+func (t *Tema[T]) IdlePeriod() int {
+	return t.Ema1.Period + t.Ema2.Period + t.Ema3.Period - 3
+}

trend/tema_test.go

@@ -0,0 +1,40 @@
+// Copyright (c) 2021-2023 Onur Cinar.
+// The source code is provided under GNU AGPLv3 License.
+// https://github.com/cinar/indicator
+
+package trend_test
+
+import (
+	"testing"
+
+	"github.com/cinar/indicator/helper"
+	"github.com/cinar/indicator/trend"
+)
+
+func TestTema(t *testing.T) {
+	type Data struct {
+		Close float64
+		Tema  float64
+	}
+
+	input, err := helper.ReadFromCsvFile[Data]("testdata/tema.csv", true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	inputs := helper.Duplicate(input, 2)
+	closing := helper.Map(inputs[0], func(d *Data) float64 { return d.Close })
+	expected := helper.Map(inputs[1], func(d *Data) float64 { return d.Tema })
+
+	tema := trend.NewTema[float64]()
+
+	actual := tema.Compute(closing)
+	actual = helper.RoundDigits(actual, 2)
+
+	expected = helper.Skip(expected, tema.IdlePeriod())
+
+	err = helper.CheckEquals(actual, expected)
+	if err != nil {
+		t.Fatal(err)
+	}
+}