RE: spirals

["Alain Tougas" <alain@xxxxxxx>]

Three spiral procedures (use different names if you want to try all three in
the same project). These procedures take an input. This means that when you
invoke the procedure, you have to provide the input, just like "fd 50"

to spiral :size
if :size > 100 [stop]
fd :size
rt 90
spiral :size + 5
end

try:
spiral 0
In this procedure, you have to change the angle "manually" in the procedure
definition in order to get a different spiral.

to spiral :size :angle
if :size > 100 [stop]
fd :size
rt :angle
spiral :size + 5 :angle
end

try:
spiral 0 120
spiral 0 123
spiral 0 117
In this procedure, you can specify the angle when you invoke the procedure.

to spiral :size :angle :limit
if :size > :limit [stop]
fd :size
rt :angle
spiral :size + 5 :angle :limit
end

try:
spiral 0 123 50
spiral 0 123 100
spiral 0 123 200
In this procedure, you can control the angle and the limit when you invoke
the procedure.

Alain

-----Original Message-----
From: mwforum-admin@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
[mailto:mwforum-admin@xxxxxxxxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Russell,
Ken
Sent: January 4, 2007 1:41 PM
To: mwforum@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Subject: spirals


This question from someone who is not a math major and who is still a novice
logo user...

I would like to create a simple spiral with the turtle using a formula. I
figured out how to do this without using a formula:

repeat 180[fd .05 rt 1]
repeat 180[fd .1 rt 1]
repeat 180[fd .15 rt 1]
repeat 180[fd .2 rt 1]
repeat 180[fd .25 rt 1]
repeat 180[fd .3 rt 1]
repeat 180[fd .35 rt 1]
repeat 180[fd .4 rt 1]
repeat 180[fd .5 rt 1]

I did a bit of research on spirals on the web and found that there are many
varieties. I'm looking for a simple one that I can explain to 6th and 7th
grade HCL students and that they can experiment with.

How would I do this using a formula?

How about a spiral using a square?

Any suggestions very much appreciated.

Ken Russell
Bellingham Schools