elliptic path

[philter5]

hey guys,
i am working on a xy pad that i made for a friend. the main goal is to drive perfectly round or elliptic paths.
every move action has autoslide and is hooked up to a lfo. but i´m stuck on how to get the XY coordinates
from the point because i use the View rotate prImitiv. for the GUI it works . has somebody an idea ow i can create
a circle for the path to P"preview" te path the rotation would take? i thought about ripping some functions from the properties panel of the SM bitmap knob (overlay circle, can be dragged,resized and show the circle path). will try this now.
but how to go for elliptic paths? also the autoslide XY doesn´t slide smooth but tbh i ave not digged deeper ....
here is tthe osm, it´s juck a quick rebuild because i don´t have the original osm here...

Edit: have to resize the osm a little, too large to upload here, limited to 2 mb

[philter5]

here is the osm. as i said i am just looking for a easy way to get the xy coordinates and a way to make elliptic paths...
would bi nice if somebody can have a short look here....thxc

[philter5]

nobody?....hmmm.... can someone point me in a direction how to get the XY path/coordinates of a circle?

[rl]

circle:
x^2 + y^2 = r^2
ellipse:
x^2/a^2 + y^2/b^2 = 1

solve this for y and you get: (two solutions each)
circle: y = +- sqrt (r^2-x^2) for x = [-r..+r]
ellipse: y = +- sqrt (b^2 * (1 - x^2/a^2) ) for x = [-a..+a]

(http://www.wolframalpha.com/input/?i=ellipse)

does this answer your question? oder habe ich was nicht verstanden?

[philter5]

hey thx a lot RL (ich weiß nicht ob du mich richtig oder falsch verstanden hast , denn ICH verstehe bis jetzt nur Bahnhof...'). that´s a point in the right direction for me, i have to investigate further...
i am very bad with math and this stuff...
i thought that there would be an easier way.

[infuzion]

DSP = math

[philter5]

DSP = math

i know infuzion, i know.... that´s the main reason why i use SM just for fun hehe
but i learn. slowly but i learn

[infuzion]

DSP = math

i know infuzion, i know.... that´s the main reason why i use SM just for fun hehe but i learn. slowly but i learn

I know I have to learn more maths myself... I wish I payed more attention in school!

[stw]

Here's an osm example of RLs formula. Maybe this helps a bit more...

ellipse path.osm

(16.43 KiB) Downloaded 54 times

[martinvicanek]

circle:
x^2 + y^2 = r^2
ellipse:
x^2/a^2 + y^2/b^2 = 1

solve this for y and you get: (two solutions each)
circle: y = +- sqrt (r^2-x^2) for x = [-r..+r]
ellipse: y = +- sqrt (b^2 * (1 - x^2/a^2) ) for x = [-a..+a]

Another representation is:
x = r*cos(t); y = r*sin(t); (circle)
x = a*cos(t); y = b*sin(t); (ellipse)
with t = [0...2*Pi]

[philter5]

circle:
x^2 + y^2 = r^2
ellipse:
x^2/a^2 + y^2/b^2 = 1

solve this for y and you get: (two solutions each)
circle: y = +- sqrt (r^2-x^2) for x = [-r..+r]
ellipse: y = +- sqrt (b^2 * (1 - x^2/a^2) ) for x = [-a..+a]

Another representation is:
x = r*cos(t); y = r*sin(t); (circle)
x = a*cos(t); y = b*sin(t); (ellipse)
with t = [0...2*Pi]

thx a lot guys...