How are you measuring the difference between these two programs? What settings are you passing to the JVM when running the Clojure version?
David On Mon, Mar 1, 2010 at 5:33 PM, John Lawrence Aspden <aspd...@googlemail.com > wrote: > Hi, the other day I was at a conference in London and learned Scala. > > As my first program I translated a favourite fractal tree program > (which I stole from: > http://marblemice.com/2009/04/26/clojure-fractal-tree/). > The programs are almost exactly the same in the two languages. > > The Scala version seems quite a lot faster than the Clojure one. I > added type hints for the Graphics objects, but there's also a > reflection warning from the JPanel proxy, which I think is > unimportant, but which I can't see how to get rid of. > > Is the reason the Clojure version is slow that recursive calls to draw- > tree are boxing and unboxing primitive types? If so is there anything > that can be done? Did I just pick a particularly bad example program? > > Or am I just missing something silly? Is there an easy way to examine > the byte-code? > Is it human-readable? Can it be done from a REPL like disassemble in > Lisp? > > ------------------------------------------- clojure version > > > (import '(javax.swing JFrame JPanel ) > '(java.awt Color Graphics Graphics2D)) > > (defn draw-tree [ #^Graphics g2d angle x y length branch-angle depth] > (if (> depth 0) > (let [new-x (- x (* length (Math/sin (Math/toRadians angle)))) > new-y (- y (* length (Math/cos (Math/toRadians angle)))) > new-length (fn [] (* length (+ 0.75 (rand 0.1)))) > new-angle (fn [op] (op angle (* branch-angle (+ 0.75 > (rand)))))] > (. g2d drawLine x y new-x new-y) > (draw-tree g2d (new-angle +) new-x new-y (new-length) branch- > angle (- depth 1)) > (draw-tree g2d (new-angle -) new-x new-y (new-length) branch- > angle (- depth 1))))) > > (defn render [ #^Graphics g w h ] > (doto g > (.setColor (Color/BLACK)) > (.fillRect 0 0 w h) > (.setColor (Color/GREEN))) > (let [init-length ( / (min w h) 5), > branch-angle (* 10 (/ w h)), > max-depth 12] > (draw-tree g 0.0 (/ w 2) h init-length branch-angle max-depth))) > > (defn create-panel [] > "Create a panel with a customised render" > > (proxy [JPanel] [] > (paintComponent [g] > (proxy-super paintComponent g) > (render g (. this getWidth) (. this getHeight))))) > > > (defn run [] > (let [frame (JFrame. "Clojure Fractal Tree") > panel (create-panel)] > (doto frame > (.add panel) > (.setSize 640 400) > (.setVisible true)))) > > (run) > > > ----------------------------------------------- scala version > > > > import scala.swing._ > import java.awt._ > import javax.swing._ > > object ScalaFractalTree { > def main(args: Array[String]){ > val frame=new JFrame("Scala Fractal Tree") > val panel=new MyPanel() > frame add panel > frame setSize (640, 400) > frame setVisible true > > } > > } > > class MyPanel extends JPanel{ > override def paintComponent(g:Graphics):Unit = { > super.paintComponent(g) > render(g, getWidth(), this.getHeight()) > > } > def render(g:Graphics, w:Int, h:Int){ > g.setColor (Color.BLACK) > g.fillRect( 0, 0, w, h) > g.setColor (Color.GREEN) > val initlength=if (w<h) w/5 else h/5 > val branchangle=10*w/h > val maxdepth=12 > drawtree( g, 0.0, w/2.0, h ,initlength, branchangle, maxdepth) > } > > def drawtree(g:Graphics, angle:Double, x:Double, y:Double, > length:Double, > branchangle:Double, depth:Double){ > if (depth>0){ > val newx= x-length*(Math.sin(Math.toRadians( angle))) > val newy= y-length*(Math.cos(Math.toRadians( angle))) > val newlength1 = length*(0.75+0.1*Math.random) > val newlength2 = length*(0.75+0.1*Math.random) > val newangle1 = angle+branchangle*(0.75+Math.random) > val newangle2 = angle-branchangle*(0.75+Math.random) > g.drawLine(x.toInt, y.toInt, newx.toInt, newy.toInt) > drawtree(g, newangle1, newx, newy, newlength1, branchangle, > depth-1) > drawtree(g, newangle2, newx, newy, newlength2, branchangle, > depth-1) > } > } > } > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com<clojure%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
