LOGO-L> Re: 3-d Moebious strip in cylindrical axis

[George Mills <mills@softronix.com>]

See attached GIF

MHELHEFNY@FRCU.EUN.EG wrote:
> 
> ;Hello George Mills
> ;Here is the true 3-d code for the moebious strip using a cylindirical
> ;co-ordinate system.
> ;the equation of the moebious band or strip is:
> ;rho = c + u*cos t/2  , y = t  , theta = c + u*sin t/2
> ;It is natural to plot the Moebious strip in those co-ordinates.
> ;N.B. This curve is a poular demo in "Mathematica"&"Maple" packages.
> ;Best Regards
> ;Mhelhefny
> ;-------------------------------------------------------------
> to 1turnon3d
> ; This is a library procedure for 3-d
> perspective
> setturtle -1
> setxyz -1200 1200 -1200
> setturtle 0 cs ht
> end
> 
> to cylpos :r :fi :y
> ;this is a library procedure for cylinderical co-ordinates
> setxyz :r*cos :fi :y :r*sin :fi
> end
> 
> to go
> 1turnon3d setpc [255 0 0]
> pu moeb1 50 moeb2 50
> end
> 
> to moeb1 :a
> for [r -:a :a 7][for[fi 0 360 9][cylpos 300+ :r* cos :fi/2 :fi 300+ :r* sin
> :fi/2 pd]pu]
> end
> 
> to moeb2 :a
> for [fi 0 360 9][for[r -:a :a 7][cylpos 300+ :r* cos :fi/2 :fi 300+ :r* sin
> :fi/2 pd]pu]
> end
> 
> to turnon3d
> ; This is a library procedure for 3-d
> perspective
> setturtle -1
> setxyz 1000 1000 1000
> setturtle 0
> end
> ;---------------------------------------------------
> Z
> 
> dir

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George Mills
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