#65 fn: PERCENTILE and PERMUTATIONA

calc.go

@@ -339,7 +339,9 @@ var tokenPriority = map[string]int{
 //    OCT2HEX
 //    ODD
 //    OR
+//    PERCENTILE
 //    PERMUT
+//    PERMUTATIONA
 //    PI
 //    POISSON.DIST
 //    POISSON
@@ -4519,6 +4521,46 @@ func (fn *formulaFuncs) min(mina bool, argsList *list.List) formulaArg {
 	return newNumberFormulaArg(min)
 }
 
+// PERCENTILE function returns the k'th percentile (i.e. the value below which
+// k% of the data values fall) for a supplied range of values and a supplied
+// k. The syntax of the function is:
+//
+//    PERCENTILE(array,k)
+//
+func (fn *formulaFuncs) PERCENTILE(argsList *list.List) formulaArg {
+	if argsList.Len() != 2 {
+		return newErrorFormulaArg(formulaErrorVALUE, "PERCENTILE requires 2 arguments")
+	}
+	array := argsList.Front().Value.(formulaArg).ToList()
+	k := argsList.Back().Value.(formulaArg).ToNumber()
+	if k.Type != ArgNumber {
+		return k
+	}
+	if k.Number < 0 || k.Number > 1 {
+		return newErrorFormulaArg(formulaErrorNA, formulaErrorNA)
+	}
+	numbers := []float64{}
+	for _, arg := range array {
+		if arg.Type == ArgError {
+			return arg
+		}
+		num := arg.ToNumber()
+		if num.Type == ArgNumber {
+			numbers = append(numbers, num.Number)
+		}
+	}
+	cnt := len(numbers)
+	sort.Float64s(numbers)
+	idx := k.Number * (float64(cnt) - 1)
+	base := math.Floor(idx)
+	if idx == base {
+		return newNumberFormulaArg(numbers[int(idx)])
+	}
+	next := base + 1
+	proportion := idx - base
+	return newNumberFormulaArg(numbers[int(base)] + ((numbers[int(next)] - numbers[int(base)]) * proportion))
+}
+
 // PERMUT function calculates the number of permutations of a specified number
 // of objects from a set of objects. The syntax of the function is:
 //
@@ -4542,6 +4584,31 @@ func (fn *formulaFuncs) PERMUT(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(math.Round(fact(number.Number) / fact(number.Number-chosen.Number)))
 }
 
+// PERMUTATIONA function calculates the number of permutations, with
+// repetitions, of a specified number of objects from a set. The syntax of
+// the function is:
+//
+//    PERMUTATIONA(number,number_chosen)
+//
+func (fn *formulaFuncs) PERMUTATIONA(argsList *list.List) formulaArg {
+	if argsList.Len() < 1 {
+		return newErrorFormulaArg(formulaErrorVALUE, "PERMUTATIONA requires 2 numeric arguments")
+	}
+	number := argsList.Front().Value.(formulaArg).ToNumber()
+	chosen := argsList.Back().Value.(formulaArg).ToNumber()
+	if number.Type != ArgNumber {
+		return number
+	}
+	if chosen.Type != ArgNumber {
+		return chosen
+	}
+	num, numChosen := math.Floor(number.Number), math.Floor(chosen.Number)
+	if num < 0 || numChosen < 0 {
+		return newErrorFormulaArg(formulaErrorNA, formulaErrorNA)
+	}
+	return newNumberFormulaArg(math.Pow(num, numChosen))
+}
+
 // SKEW function calculates the skewness of the distribution of a supplied set
 // of values. The syntax of the function is:
 //

calc_test.go

@@ -680,10 +680,16 @@ func TestCalcCellValue(t *testing.T) {
 		"=MINA(MUNIT(2))":    "0",
 		"=MINA(INT(1))":      "1",
 		"=MINA(A1:B4,MUNIT(1),INT(0),1,E1:F2,\"\")": "0",
+		// PERCENTILE
+		"=PERCENTILE(A1:A4,0.2)": "0.6",
+		"=PERCENTILE(0,0)":       "0",
 		// PERMUT
 		"=PERMUT(6,6)":  "720",
 		"=PERMUT(7,6)":  "5040",
 		"=PERMUT(10,6)": "151200",
+		// PERMUTATIONA
+		"=PERMUTATIONA(6,6)": "46656",
+		"=PERMUTATIONA(7,6)": "117649",
 		// SKEW
 		"=SKEW(1,2,3,4,3)": "-0.404796008910937",
 		"=SKEW(A1:B2)":     "0",
@@ -1473,11 +1479,22 @@ func TestCalcCellValue(t *testing.T) {
 		// MINA
 		"=MINA()":     "MINA requires at least 1 argument",
 		"=MINA(NA())": "#N/A",
+		// PERCENTILE
+		"=PERCENTILE()":       "PERCENTILE requires 2 arguments",
+		"=PERCENTILE(0,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=PERCENTILE(0,-1)":   "#N/A",
+		"=PERCENTILE(NA(),1)": "#N/A",
 		// PERMUT
 		"=PERMUT()":       "PERMUT requires 2 numeric arguments",
 		"=PERMUT(\"\",0)": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		"=PERMUT(0,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		"=PERMUT(6,8)":    "#N/A",
+		// PERMUTATIONA
+		"=PERMUTATIONA()":       "PERMUTATIONA requires 2 numeric arguments",
+		"=PERMUTATIONA(\"\",0)": "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=PERMUTATIONA(0,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=PERMUTATIONA(-1,0)":   "#N/A",
+		"=PERMUTATIONA(0,-1)":   "#N/A",
 		// SKEW
 		"=SKEW()":     "SKEW requires at least 1 argument",
 		"=SKEW(\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",