ref #65, new formula functions: F.INV and GAUSS

calc.go

@@ -417,6 +417,7 @@ type formulaFuncs struct {
 //    FALSE
 //    FIND
 //    FINDB
+//    F.INV
 //    F.INV.RT
 //    FINV
 //    FISHER
@@ -430,6 +431,7 @@ type formulaFuncs struct {
 //    FVSCHEDULE
 //    GAMMA
 //    GAMMALN
+//    GAUSS
 //    GCD
 //    GEOMEAN
 //    GESTEP
@@ -6064,6 +6066,28 @@ func (fn *formulaFuncs) GAMMALN(argsList *list.List) formulaArg {
 	return newErrorFormulaArg(formulaErrorVALUE, "GAMMALN requires 1 numeric argument")
 }
 
+// GAUSS function returns the probability that a member of a standard normal
+// population will fall between the mean and a specified number of standard
+// deviations from the mean. The syntax of the function is:
+//
+//    GAUSS(z)
+//
+func (fn *formulaFuncs) GAUSS(argsList *list.List) formulaArg {
+	if argsList.Len() != 1 {
+		return newErrorFormulaArg(formulaErrorVALUE, "GAUSS requires 1 numeric argument")
+	}
+	args := list.New().Init()
+	args.PushBack(argsList.Front().Value.(formulaArg))
+	args.PushBack(formulaArg{Type: ArgNumber, Number: 0})
+	args.PushBack(formulaArg{Type: ArgNumber, Number: 1})
+	args.PushBack(newBoolFormulaArg(true))
+	normdist := fn.NORMDIST(args)
+	if normdist.Type != ArgNumber {
+		return normdist
+	}
+	return newNumberFormulaArg(normdist.Number - 0.5)
+}
+
 // GEOMEAN function calculates the geometric mean of a supplied set of values.
 // The syntax of the function is:
 //
@@ -6208,8 +6232,9 @@ func (fn *formulaFuncs) EXPONDIST(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(lambda.Number * math.Exp(-lambda.Number*x.Number))
 }
 
-// finv is an implementation of the formula functions F.INV.RT and FINV.
+// prepareFinvArgs checking and prepare arguments for the formula function
-func (fn *formulaFuncs) finv(name string, argsList *list.List) formulaArg {
+// F.INV, F.INV.RT and FINV.
+func (fn *formulaFuncs) prepareFinvArgs(name string, argsList *list.List) formulaArg {
 	if argsList.Len() != 3 {
 		return newErrorFormulaArg(formulaErrorVALUE, fmt.Sprintf("%s requires 3 arguments", name))
 	}
@@ -6232,7 +6257,21 @@ func (fn *formulaFuncs) finv(name string, argsList *list.List) formulaArg {
 	if d2.Number < 1 || d2.Number >= math.Pow10(10) {
 		return newErrorFormulaArg(formulaErrorNUM, formulaErrorNUM)
 	}
-	return newNumberFormulaArg((1/calcBetainv(1.0-(1.0-probability.Number), d2.Number/2, d1.Number/2, 0, 1) - 1.0) * (d2.Number / d1.Number))
+	return newListFormulaArg([]formulaArg{probability, d1, d2})
+}
+
+// FdotINV function calculates the inverse of the Cumulative F Distribution
+// for a supplied probability. The syntax of the F.Inv function is:
+//
+//    F.INV(probability,deg_freedom1,deg_freedom2)
+//
+func (fn *formulaFuncs) FdotINV(argsList *list.List) formulaArg {
+	args := fn.prepareFinvArgs("F.INV", argsList)
+	if args.Type != ArgList {
+		return args
+	}
+	probability, d1, d2 := args.List[0], args.List[1], args.List[2]
+	return newNumberFormulaArg((1/calcBetainv(1-probability.Number, d2.Number/2, d1.Number/2, 0, 1) - 1) * (d2.Number / d1.Number))
 }
 
 // FdotINVdotRT function calculates the inverse of the (right-tailed) F
@@ -6242,7 +6281,12 @@ func (fn *formulaFuncs) finv(name string, argsList *list.List) formulaArg {
 //    F.INV.RT(probability,deg_freedom1,deg_freedom2)
 //
 func (fn *formulaFuncs) FdotINVdotRT(argsList *list.List) formulaArg {
-	return fn.finv("F.INV.RT", argsList)
+	args := fn.prepareFinvArgs("F.INV.RT", argsList)
+	if args.Type != ArgList {
+		return args
+	}
+	probability, d1, d2 := args.List[0], args.List[1], args.List[2]
+	return newNumberFormulaArg((1/calcBetainv(1-(1-probability.Number), d2.Number/2, d1.Number/2, 0, 1) - 1) * (d2.Number / d1.Number))
 }
 
 // FINV function calculates the inverse of the (right-tailed) F Probability
@@ -6251,7 +6295,12 @@ func (fn *formulaFuncs) FdotINVdotRT(argsList *list.List) formulaArg {
 //    FINV(probability,deg_freedom1,deg_freedom2)
 //
 func (fn *formulaFuncs) FINV(argsList *list.List) formulaArg {
-	return fn.finv("FINV", argsList)
+	args := fn.prepareFinvArgs("FINV", argsList)
+	if args.Type != ArgList {
+		return args
+	}
+	probability, d1, d2 := args.List[0], args.List[1], args.List[2]
+	return newNumberFormulaArg((1/calcBetainv(1-(1-probability.Number), d2.Number/2, d1.Number/2, 0, 1) - 1) * (d2.Number / d1.Number))
 }
 
 // NORMdotDIST function calculates the Normal Probability Density Function or

calc_test.go

@@ -838,6 +838,11 @@ func TestCalcCellValue(t *testing.T) {
 		// GAMMALN
 		"=GAMMALN(4.5)":    "2.45373657084244",
 		"=GAMMALN(INT(1))": "0",
+		// GAUSS
+		"=GAUSS(-5)":  "-0.499999713348428",
+		"=GAUSS(0)":   "0",
+		"=GAUSS(0.1)": "0.039827837277029",
+		"=GAUSS(2.5)": "0.493790334674224",
 		// GEOMEAN
 		"=GEOMEAN(2.5,3,0.5,1,3)": "1.6226711115996",
 		// HARMEAN
@@ -855,6 +860,8 @@ func TestCalcCellValue(t *testing.T) {
 		"=EXPONDIST(0.5,1,TRUE)":  "0.393469340287367",
 		"=EXPONDIST(0.5,1,FALSE)": "0.606530659712633",
 		"=EXPONDIST(2,1,TRUE)":    "0.864664716763387",
+		// F.INV
+		"=F.INV(0.9,2,5)": "3.77971607877395",
 		// FINV
 		"=FINV(0.2,1,2)":   "3.55555555555555",
 		"=FINV(0.6,1,2)":   "0.380952380952381",
@@ -2380,6 +2387,9 @@ func TestCalcCellValue(t *testing.T) {
 		"=GAMMALN(F1)":     "GAMMALN requires 1 numeric argument",
 		"=GAMMALN(0)":      "#N/A",
 		"=GAMMALN(INT(0))": "#N/A",
+		// GAUSS
+		"=GAUSS()":     "GAUSS requires 1 numeric argument",
+		"=GAUSS(\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		// GEOMEAN
 		"=GEOMEAN()":      "GEOMEAN requires at least 1 numeric argument",
 		"=GEOMEAN(0)":     "#NUM!",
@@ -2405,6 +2415,14 @@ func TestCalcCellValue(t *testing.T) {
 		"=EXPONDIST(0,1,\"\")":    "strconv.ParseBool: parsing \"\": invalid syntax",
 		"=EXPONDIST(-1,1,TRUE)":   "#NUM!",
 		"=EXPONDIST(1,0,TRUE)":    "#NUM!",
+		// F.INV
+		"=F.INV()":           "F.INV requires 3 arguments",
+		"=F.INV(\"\",1,2)":   "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=F.INV(0.2,\"\",2)": "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=F.INV(0.2,1,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=F.INV(0,1,2)":      "#NUM!",
+		"=F.INV(0.2,0.5,2)":  "#NUM!",
+		"=F.INV(0.2,1,0.5)":  "#NUM!",
 		// FINV
 		"=FINV()":           "FINV requires 3 arguments",
 		"=FINV(\"\",1,2)":   "strconv.ParseFloat: parsing \"\": invalid syntax",