diff --git a/example/example.go b/example/example.go
deleted file mode 100644
index 48f971d..0000000
--- a/example/example.go
+++ /dev/null
@@ -1,18 +0,0 @@
-package main
-
-import (
-	"generativeart"
-	"math"
-)
-
-func formula1(x, y float64) (float64, float64) {
-	return 0.18*x*x - math.Sin(y*y),
-		0.059*y*y*y - math.Cos(x*x)
-}
-
-func main() {
-	c := generativeart.NewCanva(1600, 1600, 2, 2)
-	c.FillBackground()
-	c.Draw(generativeart.NewWave(formula1))
-	c.ToPNG("g1.png")
-}
diff --git a/wave.go b/wave.go
deleted file mode 100644
index 6889963..0000000
--- a/wave.go
+++ /dev/null
@@ -1,42 +0,0 @@
-package generativeart
-
-import (
-	"math"
-
-	"github.com/fogleman/gg"
-)
-
-type Formula func(x, y float64) (float64, float64)
-
-type wave struct {
-	fn Formula
-}
-
-// NewWave returns a wave generator.
-func NewWave(fn Formula) *wave {
-	return &wave{fn: fn}
-}
-
-// Generative draws the image.
-func (w *wave) Generative(c *canva) {
-	ctex := gg.NewContextForRGBA(c.img)
-	for x := -math.Pi; x <= math.Pi; x += 0.01 {
-		for y := -math.Pi; y <= math.Pi; y += 0.01 {
-			xi, yi := w.fn(x, y)
-			var i, j int
-			if c.opts.isPolarCoodinate {
-				i, j = ConvertCartesianToPolarPixel(xi, yi, c.xaixs, c.yaixs, c.height, c.width)
-			} else {
-				i, j = ConvertCartesianToPixel(xi, yi, c.xaixs, c.yaixs, c.height, c.width)
-			}
-
-			if i < 0 || i > c.width-1 || j < 0 || j > c.height-1 {
-				continue
-			}
-
-			ctex.DrawCircle(float64(i), float64(j), c.opts.radius)
-			ctex.SetColor(c.opts.foreground)
-			ctex.Fill()
-		}
-	}
-}