Program: sierpinski triangle – Texas Instruments TI-86 User Manual

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260

Chapter 19: Applications

19APPS.DOC TI-86, Chap 19, US English Bob Fedorisko Revised: 02/13/01 2:41 PM Printed: 02/13/01 3:05 PM Page 260 of 18

Program: Sierpinski Triangle

This program creates a drawing of a widely known fractal, the Sierpinski Triangle, and
stores the drawing to the picture variable

TRI

ᕡ Select

EDIT

from the

PRGM

menu, enter

SIERP

at the

Name=

prompt, and then enter this program.

PROGRAM:SIERP
:FnOff :ClDrw
:PlOff
:AxesOff

Sets viewing

window

:0¶xMin:1¶xMax
:0¶yMin:1¶yMax
:rand¶X:rand¶Y

Begins

For

group

:For(K,1,3000)
:rand¶N

Then

group

:If N

(1 à 3 )

:Then
:.5X¶X
:.5Y¶Y
:End

Then

group

:If N>(1

à3) and N(2à3)

:Then
:.5(.5+X)¶X
:.5(1+Y)¶Y
:End

Then

group

:If N>(2

à 3 )

:Then
:.5(1+X)¶X
:.5Y¶Y
:End

Draws point

:PtOn(X,Y)

End of

For

:End

Stores picture

:StPic TRI

ᕢ On the home screen, select

SIERP

from the

PRGM

NAMES

and press b to run the program, which may run for several
minutes before completion.

ᕣ After you run the program, you can recall and display the picture

by executing

RcPic TRI