From bab29581aca957f487408532706ae19586aa234b Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Mon, 16 Sep 2024 15:39:59 +0300
Subject: [PATCH 1/2] [mathutil] Code refactoring

---
 CHANGELOG.md         | 4 ++++
 mathutil/mathutil.go | 6 +++---
 version.go           | 2 +-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5fcb405b..b4be6835 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Changelog
 
+### [13.5.1](https://kaos.sh/ek/13.5.1)
+
+- `[mathutil]` Code refactoring
+
 ### [13.5.0](https://kaos.sh/ek/13.5.0)
 
 - `[support/resources]` Added package for collecting info about CPU and memory
diff --git a/mathutil/mathutil.go b/mathutil/mathutil.go
index 6631ee96..09dea125 100644
--- a/mathutil/mathutil.go
+++ b/mathutil/mathutil.go
@@ -122,12 +122,12 @@ func Abs[N NumericNeg](val N) N {
 }
 
 // Perc calculates percentage
-func Perc[N Numeric](val1, val2 N) float64 {
-	if val2 == 0 {
+func Perc[N Numeric](current, total N) float64 {
+	if current == 0 || total == 0 {
 		return 0
 	}
 
-	return float64(val1) / float64(val2) * 100.0
+	return (float64(current) / float64(total)) * 100.0
 }
 
 // Round returns rounded value
diff --git a/version.go b/version.go
index 3df16829..9efe2a5a 100644
--- a/version.go
+++ b/version.go
@@ -8,4 +8,4 @@ package ek
 // ////////////////////////////////////////////////////////////////////////////////// //
 
 // VERSION is current ek package version
-const VERSION = "13.5.0"
+const VERSION = "13.5.1"

From 56954b653bae6c0e7af8dd91f5e107eb44bb6eeb Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Mon, 16 Sep 2024 15:46:36 +0300
Subject: [PATCH 2/2] [mathutil] Add method 'FromPerc'

---
 CHANGELOG.md              | 1 +
 mathutil/example_test.go  | 6 ++++++
 mathutil/mathutil.go      | 9 +++++++++
 mathutil/mathutil_test.go | 8 ++++++++
 4 files changed, 24 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b4be6835..dbadec37 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ### [13.5.1](https://kaos.sh/ek/13.5.1)
 
+- `[mathutil]` Added method `FromPerc`
 - `[mathutil]` Code refactoring
 
 ### [13.5.0](https://kaos.sh/ek/13.5.0)
diff --git a/mathutil/example_test.go b/mathutil/example_test.go
index 9cb5cd74..e0c8285d 100644
--- a/mathutil/example_test.go
+++ b/mathutil/example_test.go
@@ -83,6 +83,12 @@ func ExamplePerc() {
 	// 30%
 }
 
+func ExampleFromPerc() {
+	fmt.Printf("%g\n", FromPerc(15.0, 2860))
+	// Output:
+	// 429
+}
+
 func ExampleRound() {
 	fmt.Println(Round(3.14159, 2))
 	// Output:
diff --git a/mathutil/mathutil.go b/mathutil/mathutil.go
index 09dea125..ff2795bd 100644
--- a/mathutil/mathutil.go
+++ b/mathutil/mathutil.go
@@ -130,6 +130,15 @@ func Perc[N Numeric](current, total N) float64 {
 	return (float64(current) / float64(total)) * 100.0
 }
 
+// FromPerc calculates value from percentage
+func FromPerc(perc float64, total float64) float64 {
+	if perc <= 0 || total == 0 {
+		return 0
+	}
+
+	return (total / 100.0) * perc
+}
+
 // Round returns rounded value
 func Round(v float64, p int) float64 {
 	pow := math.Pow(10, float64(p))
diff --git a/mathutil/mathutil_test.go b/mathutil/mathutil_test.go
index e8da32a0..818192df 100644
--- a/mathutil/mathutil_test.go
+++ b/mathutil/mathutil_test.go
@@ -68,3 +68,11 @@ func (s *MathUtilSuite) TestPerc(c *C) {
 	c.Assert(Perc(100, 100), Equals, 100.0)
 	c.Assert(Perc(200, 100), Equals, 200.0)
 }
+
+func (s *MathUtilSuite) TestFromPerc(c *C) {
+	c.Assert(FromPerc(0, 0), Equals, 0.0)
+	c.Assert(FromPerc(100, 0), Equals, 0.0)
+	c.Assert(FromPerc(-1, 1000), Equals, 0.0)
+	c.Assert(FromPerc(250, 100), Equals, 250.0)
+	c.Assert(FromPerc(25.55, -100), Equals, -25.55)
+}