Merge pull request #217 from pratikmota/mathfunc-part-6

[Adding math functions] Support Erf, Erfc, Erfcinv and Erfinv math functions
refaktor · May 28, 2024 · 55354ec · 55354ec
2 parents e3928b7 + fa9af19
commit 55354ec
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diff --git a/evaldo/builtins_math.go b/evaldo/builtins_math.go
@@ -398,6 +398,62 @@ var Builtins_math = map[string]*env.Builtin{
 			}
 		},
 	},
+	"erf": {
+		Argsn: 1,
+		Doc:   "Returns the error function of value.",
+		Fn: func(ps *env.ProgramState, arg0 env.Object, arg1 env.Object, arg2 env.Object, arg3 env.Object, arg4 env.Object) env.Object {
+			switch val := arg0.(type) {
+			case env.Integer:
+				return *env.NewDecimal(math.Erf(float64(val.Value)))
+			case env.Decimal:
+				return *env.NewDecimal(math.Erf(val.Value))
+			default:
+				return MakeArgError(ps, 1, []env.Type{env.IntegerType, env.DecimalType}, "erf")
+			}
+		},
+	},
+	"erfc": {
+		Argsn: 1,
+		Doc:   "Returns the complementary error function of value.",
+		Fn: func(ps *env.ProgramState, arg0 env.Object, arg1 env.Object, arg2 env.Object, arg3 env.Object, arg4 env.Object) env.Object {
+			switch val := arg0.(type) {
+			case env.Integer:
+				return *env.NewDecimal(math.Erfc(float64(val.Value)))
+			case env.Decimal:
+				return *env.NewDecimal(math.Erfc(val.Value))
+			default:
+				return MakeArgError(ps, 1, []env.Type{env.IntegerType, env.DecimalType}, "erfc")
+			}
+		},
+	},
+	"erfcinv": {
+		Argsn: 1,
+		Doc:   "Returns the inverse of erfc(x) function.",
+		Fn: func(ps *env.ProgramState, arg0 env.Object, arg1 env.Object, arg2 env.Object, arg3 env.Object, arg4 env.Object) env.Object {
+			switch val := arg0.(type) {
+			case env.Integer:
+				return *env.NewDecimal(math.Erfcinv(float64(val.Value)))
+			case env.Decimal:
+				return *env.NewDecimal(math.Erfcinv(val.Value))
+			default:
+				return MakeArgError(ps, 1, []env.Type{env.IntegerType, env.DecimalType}, "erfcinv")
+			}
+		},
+	},
+	"erfinv": {
+		Argsn: 1,
+		Doc:   "Returns the inverse error function of value.",
+		Fn: func(ps *env.ProgramState, arg0 env.Object, arg1 env.Object, arg2 env.Object, arg3 env.Object, arg4 env.Object) env.Object {
+			switch val := arg0.(type) {
+			case env.Integer:
+				return *env.NewDecimal(math.Erfinv(float64(val.Value)))
+			case env.Decimal:
+				return *env.NewDecimal(math.Erfinv(val.Value))
+			default:
+				return MakeArgError(ps, 1, []env.Type{env.IntegerType, env.DecimalType}, "erfinv")
+			}
+		},
+	},
 	"pi": {
 		Argsn: 0,
 		Doc:   "Return Pi constant.",

diff --git a/tests/misc.rye b/tests/misc.rye
@@ -430,6 +430,40 @@ section "Math functions"
 		equal { do\in math { dim 8 -1 } } 9.000000
 		equal { do\in math { dim -4 -2 } } 0.000000
 	}
+
+	group "erf"
+	mold\nowrap "" 
+	{ { string } }
+	{
+		equal { do\in math { erf 1.5 } } 0.9661051464753108
+	}
+
+	group "erfc"
+	mold\nowrap "" 
+	{ { string } }
+	{
+		equal { do\in math { erfc 1.5 } } 0.033894853524689274
+	}
+
+	group "erfcinv"
+	mold\nowrap "" 
+	{ { string } }
+	{
+		equal { do\in math { erfcinv 1.5 } } -0.4769362762044699
+		equal { do\in math { erfcinv 0 } } "+Inf"
+		equal { do\in math { erfcinv 2 } } "-Inf"
+		equal { do\in math { erfcinv 2.2 } } "NaN"
+	}
+
+	group "erfinv"
+	mold\nowrap "" 
+	{ { string } }
+	{
+		equal { do\in math { erfcinv 0.5 } } 0.4769362762044699
+		equal { do\in math { erfcinv 1 } } "+Inf"
+		equal { do\in math { erfcinv -1 } } "-Inf"
+		equal { do\in math { erfcinv 1.5 } } "NaN"
+	}
 
 }