1. Calculating points in a circle
- Posted by "D Stanger" <dstanger at belco.bc.ca>
Nov 06, 2004
-
Last edited Nov 07, 2004
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Hello all,
Here is a question for those with more mathematical knowlege than I possess
[almost anyone]:
Is there a formula for determing the X, Y points on the screen around the
circumference of a circle if its radius and center point is known?
This sort of thing has me waking up with night sweats ^__^;;
Thanks in advance,
David S.
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<DIV><FONT face=Arial size=2>Hello all,</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Here is a question for those with more mathematical
knowlege than I possess [almost anyone]:<BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Is there a formula for determing the X, Y
points on the screen around the circumference of a circle if its radius and
center point is known?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This sort of thing has me waking up with night
sweats ^__^;;</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks in advance,</FONT></DIV>
<DIV><FONT face=Arial size=2>David S.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2><BR>---<BR>Outgoing mail is certified Virus Free
unless this too is a virus.....hmmmm.<BR>Checked by AVG anti-virus system (<A
href="http://www.grisoft.com">http://www.grisoft.com</A>).<BR>Version: 6.0.788 /
Virus Database: 533 - Release Date: 11/1/2004</DIV></FONT></BODY></HTML>
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2. Re: Calculating points in a circle
- Posted by Jason Mirwald <jmirwald at ameritech.net>
Nov 06, 2004
-
Last edited Nov 07, 2004
Given just the radius and center point is kind-a rough, but trig should
be able to solve it for you, if you know at least one other variable. If
you are trying to solve from the horizontal plane maybe?
jami
3. Re: Calculating points in a circle
Try this:
a is angle
r is radius(or was I correct the last time saying diameter...?)
x and y are the coordinates
Resize the window to see the circle.
include Win32Lib.ew
without warning
--------------------------------------------------------------------------------
-- Window w
constant w = createEx( Window, "Window1", 0, Default, Default, 400, 300, 0, 0 )
procedure w_onResize (integer self, integer event, sequence params)--params is (
int style, int cx, int cy )
int x,y,r
repaintWindow(w)
r=floor(params[2]/2)
for a=-PI to PI by 1/(r*PI) do
x=floor(sin(a)*r)+r
y=floor(cos(a)*r)+r
setPixel(w,x,y,0)
--?{x,y}
end for
end procedure
setHandler( w, w32HResize, routine_id("w_onResize"))
WinMain( w,Normal )
4. Re: Calculating points in a circle
This will give you a simple circle.
angle is from -PI to PI.
Calculating how to increment angle
still needs to be figured out.
x=sin(angle)*diameter
y=cos(angle)*diameter
5. Re: Calculating points in a circle
My second reply(it displayed before this one) is better.
CoJaBo wrote:
>
> This will give you a simple circle.
> angle is from -PI to PI.
> Calculating how to increment angle
> still needs to be figured out.
>
> x=sin(angle)*diameter
> y=cos(angle)*diameter
>
>
