Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

Help for Mathematica

• To: mathgroup at smc.vnet.net
• Subject: [mg34139] Help for Mathematica
• From: bardin.caroline at caramail.com (Caroline)
• Date: Sun, 5 May 2002 04:48:49 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

Hello! I have a little problem with mathematica. Could someone help
me, please?
Well, I have this package called turtle and I must write a function
"tree" with arguments : length, depth, angle, ratio to draw a binary
tree. Then I must also write the Sierpinski's triangle with the
function tree.
Thanks for helping me.
Caro

P.S : Sorry for the bad english, I'm french.

BeginPackage["Turtle`]
(* This package provides four functions for controlling the
movement and orientation of a "turtle" graphics device. It
maintains a list of the points visited by the turtle in "path",
which can then be manipulated and displayed as a Graphics
object. The calling routine must begin by invoking initialize[];
it can end by either showturtlepath, or by its own
Show[Graphics[Line[path]], options] command. *)

initialize::usage = "initialize[p;{0, 0}] places the turtle at
 p (default is {0, 0}), points it in direction {1, 0}, and
sets path to {p}."

showturtlepath::usage = "showturtlepath" displays the turtle's
path."

right::usage = "right[a] turns the turtle a degree to the right."

left::usage = "left[a] turns the turtle a degree to the left."

forward::usage = "forward[s] moves the turtle forward  s  units,
and appends the coordinates of the new position to path."

back::usage = "back[s] moves the turtle back  s  units, and
appends the coordinates of the new position to path."

Begin["Turtle`Private`"]

initialize[start_:{0, 0}] := (X = start; U = {1, 0}; path = {X})
         
right[a_] :=
 U = {{Cos[aa = a Degree//N], Sin[aa]}, {-Sin[aa], Cos[aa]}} . U
         
left[a_] :=
 U = {{Cos[aa = a Degree//N], -Sin[aa]}, {Sin[aa], Cos[aa]}} . U
         
forward[s_] := AppendTo[path, X += s U]
         
back[s_] := AppendTo[path, X -= s U]

showturtlepath := Show[Graphics[{{RGBColor[0, 0, 1], Line[path]}}],
                       PlotRange->All, AspectRatio->1]

End[]

EndPackage[]

• Follow-Ups:
  • Re: Help for Mathematica
    • From: Murray Eisenberg <murraye@attbi.com>