- polar plots
All these spirals are drawn using polar co-ordinates. See Spirals for spirals drawn using calculation of curvature.
This draws a ten turn Archimedes spiral.
To New
# set default screen, pen and turtle values
ResetAll SetScreenSize [400 400] HideTurtle
SetSC Black SetPC Green SetPS 1 PenUp
End
To P2R :Radius :Angle
Make "X :Radius * Cos :Angle
Make "Y :Radius * Sin :Angle
Output List :X :Y
End
To Spiral :Angle
# Archimides Spiral
Make "Radius :Angle/20
End
To Go
New SetPC Yellow
For [Angle 0 3600] [
Spiral :Angle
SetPos P2R :Radius :Angle PenDown]
End
For Fermats spiral, Radius is proportional to the square root of the Angle. Copy and paste to update the spiral procedure.
To Spiral :Angle
# Fermats Spiral
Make "Radius 3*Power :Angle 0.5
End
An equiangular spiral grows very quickly.
To Spiral :Angle
# Equiangular Spiral
Make "Radius Power 1.002 :Angle
End
This adds a small ripple to an Archimedes spiral, giving an illusion of petals. You will need to increase the number of steps to 8860.
To Spiral :Angle
# Archimides Daisy
Make "Offset Sin 7.05*:Angle
Make "Radius :Angle/52 + (Power (:Angle/2000) 2) * :Offset
SetPC ( List 0 (Round 127.5 * (1+:Offset)) 255 )
End