From 8b04f810090aa40002e4a2240e6bea7ea3a9c417 Mon Sep 17 00:00:00 2001
From: D0LeD <vovaumni@gmail.com>
Date: Wed, 17 Jan 2024 21:53:19 +0200
Subject: [PATCH] without drawing

---
 main.go | 82 +++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 59 insertions(+), 23 deletions(-)

diff --git a/main.go b/main.go
index e39985b..caf39e0 100644
--- a/main.go
+++ b/main.go
@@ -1,33 +1,69 @@
 package main
 
-import (
-	"image"
-	"log"
-	"time"
+import "fmt"
 
-	"github.com/hajimehoshi/ebiten/v2"
-)
+type functiontype struct {
+	k, b float64
+}
 
-func f(x float64) float64  { return x*x + 5*x - 3 }
-func df(x float64) float64 { return 2*x + 5 }
+type coord struct {
+	x, y float64
+}
 
 func main() {
-	ebiten.SetWindowSize(640, 480)
-	ebiten.SetWindowTitle("Gradient descent")
-
-	img := make(chan *image.RGBA, 1)
-	go func() {
-		p := Plot(-5, 0, 0.1, f)
-		x := 0.0
-		img <- p(x)
-		for i := 0; i < 50; i++ {
-			time.Sleep(30 * time.Millisecond)
-			x -= df(x) * 0.1
-			img <- p(x)
+	points := []coord{{0, 1}, {-0.5, 0}, {0.5, 2}, {1, 3}, {2.5, 6}}
+	learnRate := 0.01
+	epochs := 1000
+
+	train(points, learnRate, epochs)
+}
+
+func train(points []coord, learnRate float64, epochs int) {
+	n := float64(len(points))
+	var line functiontype
+
+	for epoch := 1; epoch <= epochs; epoch++ {
+		fxi := findFxi(points, line)
+		er := findEr(points, fxi)
+
+		var sumk, sumb float64
+		for i, j := range er {
+			sumk += j * points[i].x
+			sumb += j
 		}
-	}()
 
-	if err := ebiten.RunGame(&App{Img: img}); err != nil {
-		log.Fatal(err)
+		line.k += (2 / n) * sumk * learnRate
+		line.b += (2 / n) * sumb * learnRate
+
+		loss := average(er)
+
+		if epoch%100 == 0 {
+			fmt.Printf("Epoch %d, Loss: %f\n", epoch, loss)
+		}
 	}
 }
+
+func findFxi(points []coord, line functiontype) (fxi []float64) {
+	for _, j := range points {
+		fxi = append(fxi, line.k*j.x+line.b)
+	}
+	return fxi
+}
+
+func findEr(points []coord, fxi []float64) (er []float64) {
+	for i, j := range points {
+		er = append(er, j.y-fxi[i])
+	}
+	return er
+}
+
+func sliceSum(s []float64) (sum float64) {
+	for _, j := range s {
+		sum += j
+	}
+	return sum
+}
+
+func average(s []float64) float64 {
+	return sliceSum(s) / float64(len(s))
+}