fn: ABS, GCD, LCM, POWER, PRODUCT, SIGN, SQRT, SUM, QUOTIENT

calc.go

@@ -412,7 +412,7 @@ func (f *File) parseReference(sheet, reference string) (result []string, err err
 // rangeResolver extract value as string from given reference and range list.
 // This function will not ignore the empty cell. Note that the result of 3D
 // range references may be different from Excel in some cases, for example,
-// A1:A2:A2:B3 in Excel will include B2, but we wont.
+// A1:A2:A2:B3 in Excel will include B1, but we wont.
 func (f *File) rangeResolver(cellRefs, cellRanges *list.List) (result []string, err error) {
 	filter := map[string]string{}
 	// extract value from ranges
@@ -475,14 +475,58 @@ func callFuncByName(receiver interface{}, name string, params []reflect.Value) (
 
 // Math and Trigonometric functions
 
-// SUM function adds together a supplied set of numbers and returns the sum of
-// these values. The syntax of the function is:
+// ABS function returns the absolute value of any supplied number. The syntax
+// of the function is:
 //
-//    SUM(number1,[number2],...)
+//   ABS(number)
 //
-func (fn *formulaFuncs) SUM(argsStack *Stack) (result string, err error) {
+func (fn *formulaFuncs) ABS(argsStack *Stack) (result string, err error) {
+	if argsStack.Len() != 1 {
+		err = errors.New("ABS requires 1 numeric arguments")
+		return
+	}
 	var val float64
-	var sum float64
+	val, err = strconv.ParseFloat(argsStack.Pop().(efp.Token).TValue, 64)
+	if err != nil {
+		return
+	}
+	result = fmt.Sprintf("%g", math.Abs(val))
+	return
+}
+
+// gcd returns the greatest common divisor of two supplied integers.
+func gcd(x, y float64) float64 {
+	x, y = math.Trunc(x), math.Trunc(y)
+	if x == 0 {
+		return y
+	}
+	if y == 0 {
+		return x
+	}
+	for x != y {
+		if x > y {
+			x = x - y
+		} else {
+			y = y - x
+		}
+	}
+	return x
+}
+
+// GCD function returns the greatest common divisor of two or more supplied
+// integers.The syntax of the function is:
+//
+//   GCD(number1,[number2],...)
+//
+func (fn *formulaFuncs) GCD(argsStack *Stack) (result string, err error) {
+	if argsStack.Len() == 0 {
+		err = errors.New("GCD requires at least 1 argument")
+		return
+	}
+	var (
+		val  float64
+		nums = []float64{}
+	)
 	for !argsStack.Empty() {
 		token := argsStack.Pop().(efp.Token)
 		if token.TValue == "" {
@@ -492,21 +536,51 @@ func (fn *formulaFuncs) SUM(argsStack *Stack) (result string, err error) {
 		if err != nil {
 			return
 		}
-		sum += val
+		nums = append(nums, val)
 	}
-	result = fmt.Sprintf("%g", sum)
+	if nums[0] < 0 {
+		err = errors.New("GCD only accepts positive arguments")
+		return
+	}
+	if len(nums) == 1 {
+		result = fmt.Sprintf("%g", nums[0])
+		return
+	}
+	cd := nums[0]
+	for i := 1; i < len(nums); i++ {
+		if nums[i] < 0 {
+			err = errors.New("GCD only accepts positive arguments")
+			return
+		}
+		cd = gcd(cd, nums[i])
+	}
+	result = fmt.Sprintf("%g", cd)
 	return
 }
 
-// PRODUCT function returns the product (multiplication) of a supplied set of numerical values.
-// The syntax of the function is:
+// lcm returns the least common multiple of two supplied integers.
+func lcm(a, b float64) float64 {
+	a = math.Trunc(a)
+	b = math.Trunc(b)
+	if a == 0 && b == 0 {
+		return 0
+	}
+	return a * b / gcd(a, b)
+}
+
+// LCM function returns the least common multiple of two or more supplied
+// integers. The syntax of the function is:
 //
-//    PRODUCT(number1,[number2],...)
+//   LCM(number1,[number2],...)
 //
-func (fn *formulaFuncs) PRODUCT(argsStack *Stack) (result string, err error) {
+func (fn *formulaFuncs) LCM(argsStack *Stack) (result string, err error) {
+	if argsStack.Len() == 0 {
+		err = errors.New("LCM requires at least 1 argument")
+		return
+	}
 	var (
-		val     float64
-		product float64 = 1
+		val  float64
+		nums = []float64{}
 	)
 	for !argsStack.Empty() {
 		token := argsStack.Pop().(efp.Token)
@@ -517,13 +591,29 @@ func (fn *formulaFuncs) PRODUCT(argsStack *Stack) (result string, err error) {
 		if err != nil {
 			return
 		}
-		product = product * val
+		nums = append(nums, val)
 	}
-	result = fmt.Sprintf("%g", product)
+	if nums[0] < 0 {
+		err = errors.New("LCM only accepts positive arguments")
+		return
+	}
+	if len(nums) == 1 {
+		result = fmt.Sprintf("%g", nums[0])
+		return
+	}
+	cm := nums[0]
+	for i := 1; i < len(nums); i++ {
+		if nums[i] < 0 {
+			err = errors.New("LCM only accepts positive arguments")
+			return
+		}
+		cm = lcm(cm, nums[i])
+	}
+	result = fmt.Sprintf("%g", cm)
 	return
 }
 
-// PRODUCT function calculates a given number, raised to a supplied power.
+// POWER function calculates a given number, raised to a supplied power.
 // The syntax of the function is:
 //
 //    POWER(number,power)
@@ -554,8 +644,62 @@ func (fn *formulaFuncs) POWER(argsStack *Stack) (result string, err error) {
 	return
 }
 
-// SQRT function calculates the positive square root of a supplied number.
-// The syntax of the function is:
+// PRODUCT function returns the product (multiplication) of a supplied set of
+// numerical values. The syntax of the function is:
+//
+//    PRODUCT(number1,[number2],...)
+//
+func (fn *formulaFuncs) PRODUCT(argsStack *Stack) (result string, err error) {
+	var (
+		val     float64
+		product float64 = 1
+	)
+	for !argsStack.Empty() {
+		token := argsStack.Pop().(efp.Token)
+		if token.TValue == "" {
+			continue
+		}
+		val, err = strconv.ParseFloat(token.TValue, 64)
+		if err != nil {
+			return
+		}
+		product = product * val
+	}
+	result = fmt.Sprintf("%g", product)
+	return
+}
+
+// SIGN function returns the arithmetic sign (+1, -1 or 0) of a supplied
+// number. I.e. if the number is positive, the Sign function returns +1, if
+// the number is negative, the function returns -1 and if the number is 0
+// (zero), the function returns 0. The syntax of the function is:
+//
+//   SIGN(number)
+//
+func (fn *formulaFuncs) SIGN(argsStack *Stack) (result string, err error) {
+	if argsStack.Len() != 1 {
+		err = errors.New("SIGN requires 1 numeric arguments")
+		return
+	}
+	var val float64
+	val, err = strconv.ParseFloat(argsStack.Pop().(efp.Token).TValue, 64)
+	if err != nil {
+		return
+	}
+	if val < 0 {
+		result = "-1"
+		return
+	}
+	if val > 0 {
+		result = "1"
+		return
+	}
+	result = "0"
+	return
+}
+
+// SQRT function calculates the positive square root of a supplied number. The
+// syntax of the function is:
 //
 //    SQRT(number)
 //
@@ -577,8 +721,31 @@ func (fn *formulaFuncs) SQRT(argsStack *Stack) (result string, err error) {
 	return
 }
 
-// QUOTIENT function returns the integer portion of a division between two supplied numbers.
-// The syntax of the function is:
+// SUM function adds together a supplied set of numbers and returns the sum of
+// these values. The syntax of the function is:
+//
+//    SUM(number1,[number2],...)
+//
+func (fn *formulaFuncs) SUM(argsStack *Stack) (result string, err error) {
+	var val float64
+	var sum float64
+	for !argsStack.Empty() {
+		token := argsStack.Pop().(efp.Token)
+		if token.TValue == "" {
+			continue
+		}
+		val, err = strconv.ParseFloat(token.TValue, 64)
+		if err != nil {
+			return
+		}
+		sum += val
+	}
+	result = fmt.Sprintf("%g", sum)
+	return
+}
+
+// QUOTIENT function returns the integer portion of a division between two
+// supplied numbers. The syntax of the function is:
 //
 //   QUOTIENT(numerator,denominator)
 //

calc_test.go

@@ -18,6 +18,35 @@ func TestCalcCellValue(t *testing.T) {
 	}
 
 	mathCalc := map[string]string{
+		// ABS
+		"=ABS(-1)":    "1",
+		"=ABS(-6.5)":  "6.5",
+		"=ABS(6.5)":   "6.5",
+		"=ABS(0)":     "0",
+		"=ABS(2-4.5)": "2.5",
+		// GCD
+		"=GCD(1,5)":      "1",
+		"=GCD(15,10,25)": "5",
+		"=GCD(0,8,12)":   "4",
+		"=GCD(7,2)":      "1",
+		// LCM
+		"=LCM(1,5)":      "5",
+		"=LCM(15,10,25)": "150",
+		"=LCM(1,8,12)":   "24",
+		"=LCM(7,2)":      "14",
+		// POWER
+		"=POWER(4,2)": "16",
+		// PRODUCT
+		"=PRODUCT(3,6)": "18",
+		// SIGN
+		"=SIGN(9.5)":        "1",
+		"=SIGN(-9.5)":       "-1",
+		"=SIGN(0)":          "0",
+		"=SIGN(0.00000001)": "1",
+		"=SIGN(6-7)":        "-1",
+		// SQRT
+		"=SQRT(4)": "2",
+		// SUM
 		"=SUM(1,2)":                           "3",
 		"=SUM(1,2+3)":                         "6",
 		"=SUM(SUM(1,2),2)":                    "5",
@@ -31,10 +60,6 @@ func TestCalcCellValue(t *testing.T) {
 		"=((3+5*2)+3)/5+(-6)/4*2+3":           "3.2",
 		"=1+SUM(SUM(1,2*3),4)*-4/2+5+(4+2)*3": "2",
 		"=1+SUM(SUM(1,2*3),4)*4/3+5+(4+2)*3":  "38.666666666666664",
-		// POWER
-		"=POWER(4,2)": "16",
-		// SQRT
-		"=SQRT(4)": "2",
 		// QUOTIENT
 		"=QUOTIENT(5, 2)":     "2",
 		"=QUOTIENT(4.5, 3.1)": "1",
@@ -48,10 +73,23 @@ func TestCalcCellValue(t *testing.T) {
 		assert.Equal(t, expected, result)
 	}
 	mathCalcError := map[string]string{
+		// ABS
+		"=ABS(1,2)": "ABS requires 1 numeric arguments",
+		"=ABS(~)":   `cannot convert cell "~" to coordinates: invalid cell name "~"`,
+		// GCD
+		"=GCD()":     "GCD requires at least 1 argument",
+		"=GCD(-1)":   "GCD only accepts positive arguments",
+		"=GCD(1,-1)": "GCD only accepts positive arguments",
+		// LCM
+		"=LCM()":     "LCM requires at least 1 argument",
+		"=LCM(-1)":   "LCM only accepts positive arguments",
+		"=LCM(1,-1)": "LCM only accepts positive arguments",
 		// POWER
 		"=POWER(0,0)":  "#NUM!",
 		"=POWER(0,-1)": "#DIV/0!",
 		"=POWER(1)":    "POWER requires 2 numeric arguments",
+		// SIGN
+		"=SIGN()": "SIGN requires 1 numeric arguments",
 		// SQRT
 		"=SQRT(-1)":  "#NUM!",
 		"=SQRT(1,2)": "SQRT requires 1 numeric arguments",
@@ -68,6 +106,9 @@ func TestCalcCellValue(t *testing.T) {
 	}
 
 	referenceCalc := map[string]string{
+		// PRODUCT
+		"=PRODUCT(Sheet1!A1:Sheet1!A1:A2,A2)": "4",
+		// SUM
 		"=A1/A3":                          "0.3333333333333333",
 		"=SUM(A1:A2)":                     "3",
 		"=SUM(Sheet1!A1,A2)":              "3",
@@ -77,8 +118,6 @@ func TestCalcCellValue(t *testing.T) {
 		"=1+SUM(SUM(A1+A2/A3)*(2-3),2)":   "1.3333333333333335",
 		"=A1/A2/SUM(A1:A2:B1)":            "0.07142857142857142",
 		"=A1/A2/SUM(A1:A2:B1)*A3":         "0.21428571428571427",
-		// PRODUCT
-		"=PRODUCT(Sheet1!A1:Sheet1!A1:A2,A2)": "4",
 	}
 	for formula, expected := range referenceCalc {
 		f := prepareData()