From c5c6f66b0a4eed1046c42225c3a2161f96b46715 Mon Sep 17 00:00:00 2001
From: Pratik Mota <pratik@pratikmota.com>
Date: Sun, 26 May 2024 15:33:00 +0530
Subject: [PATCH 1/6] Adding Erf math function

---
 evaldo/builtins_math.go | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/evaldo/builtins_math.go b/evaldo/builtins_math.go
index 97b070de..5f98441c 100644
--- a/evaldo/builtins_math.go
+++ b/evaldo/builtins_math.go
@@ -398,6 +398,20 @@ 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")
+			}
+		},
+	},
 	"pi": {
 		Argsn: 0,
 		Doc:   "Return Pi constant.",

From 31a077702c3107a0a939b0002594353c8151f6c7 Mon Sep 17 00:00:00 2001
From: Pratik Mota <pratik@pratikmota.com>
Date: Sun, 26 May 2024 15:40:46 +0530
Subject: [PATCH 2/6] Adding erfc math function

---
 evaldo/builtins_math.go | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/evaldo/builtins_math.go b/evaldo/builtins_math.go
index 5f98441c..532cbeb3 100644
--- a/evaldo/builtins_math.go
+++ b/evaldo/builtins_math.go
@@ -412,6 +412,20 @@ var Builtins_math = map[string]*env.Builtin{
 			}
 		},
 	},
+	"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")
+			}
+		},
+	},
 	"pi": {
 		Argsn: 0,
 		Doc:   "Return Pi constant.",

From 210cd8f1cb47b73015336324bbfb0e18750b0ace Mon Sep 17 00:00:00 2001
From: Pratik Mota <pratik@pratikmota.com>
Date: Sun, 26 May 2024 15:50:04 +0530
Subject: [PATCH 3/6] Adding erfcinv match function

---
 evaldo/builtins_math.go | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/evaldo/builtins_math.go b/evaldo/builtins_math.go
index 532cbeb3..1f795f34 100644
--- a/evaldo/builtins_math.go
+++ b/evaldo/builtins_math.go
@@ -426,6 +426,26 @@ var Builtins_math = map[string]*env.Builtin{
 			}
 		},
 	},
+	"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:
+				if val.Value < 0 || val.Value > 2 {
+					return MakeBuiltinError(ps, "Invalid input: erfcinv is only defined for 0 <= x <= 2.", "erfcinv")
+				}
+				return *env.NewDecimal(math.Erfcinv(float64(val.Value)))
+			case env.Decimal:
+				if val.Value < 0 || val.Value > 2 {
+					return MakeBuiltinError(ps, "Invalid input: erfcinv is only defined for 0 <= x <= 2.", "erfcinv")
+				}
+				return *env.NewDecimal(math.Erfcinv(val.Value))
+			default:
+				return MakeArgError(ps, 1, []env.Type{env.IntegerType, env.DecimalType}, "erfcinv")
+			}
+		},
+	},
 	"pi": {
 		Argsn: 0,
 		Doc:   "Return Pi constant.",

From 5b6b4d55678252064094d312ce758ecf0261ef7f Mon Sep 17 00:00:00 2001
From: Pratik Mota <pratik@pratikmota.com>
Date: Sun, 26 May 2024 16:01:39 +0530
Subject: [PATCH 4/6] Adding Erfinv math function

---
 evaldo/builtins_math.go | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/evaldo/builtins_math.go b/evaldo/builtins_math.go
index 1f795f34..f6443cf6 100644
--- a/evaldo/builtins_math.go
+++ b/evaldo/builtins_math.go
@@ -432,20 +432,28 @@ var Builtins_math = map[string]*env.Builtin{
 		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:
-				if val.Value < 0 || val.Value > 2 {
-					return MakeBuiltinError(ps, "Invalid input: erfcinv is only defined for 0 <= x <= 2.", "erfcinv")
-				}
 				return *env.NewDecimal(math.Erfcinv(float64(val.Value)))
 			case env.Decimal:
-				if val.Value < 0 || val.Value > 2 {
-					return MakeBuiltinError(ps, "Invalid input: erfcinv is only defined for 0 <= x <= 2.", "erfcinv")
-				}
 				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.",

From 68027e55b3123405882cfb67f1e09d77fe4dd6fb Mon Sep 17 00:00:00 2001
From: Pratik Mota <pratik@pratikmota.com>
Date: Sun, 26 May 2024 16:25:53 +0530
Subject: [PATCH 5/6] Adding test cases for erf functions

---
 tests/misc.rye | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/tests/misc.rye b/tests/misc.rye
index 73f76bbf..4903b9d6 100644
--- 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
+	}
 	
 }
 

From fa9af19a9b421c5509316742586dad1b7442c53c Mon Sep 17 00:00:00 2001
From: Pratik Mota <pratik@pratikmota.com>
Date: Sun, 26 May 2024 16:49:32 +0530
Subject: [PATCH 6/6] Adding inf,  and NaN values

---
 tests/misc.rye | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tests/misc.rye b/tests/misc.rye
index 4903b9d6..1c1eaa7a 100644
--- a/tests/misc.rye
+++ b/tests/misc.rye
@@ -450,9 +450,9 @@ section "Math functions"
 	{ { 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
+		equal { do\in math { erfcinv 0 } } "+Inf"
+		equal { do\in math { erfcinv 2 } } "-Inf"
+		equal { do\in math { erfcinv 2.2 } } "NaN"
 	}
 
 	group "erfinv"
@@ -460,9 +460,9 @@ section "Math functions"
 	{ { 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
+		equal { do\in math { erfcinv 1 } } "+Inf"
+		equal { do\in math { erfcinv -1 } } "-Inf"
+		equal { do\in math { erfcinv 1.5 } } "NaN"
 	}
 	
 }