Re: Can anyone help me fix my circle math?

["Chris Cheatham" <chris@xxxxxxxxxxxxxxxxxx>]

Thanks for having a look Gary. Have a look at the two pics attached. One
shows with sq rt of sine and one without. With sine looks better, but not
perfect. Truth is I arrived at that by playing with it to see what looked
best. But I think you got at the problem. I am taking the sine of 180* times
the index value which is from 0 to 1 instead of taking sine of the angle.
This index is a linear function, and 180* this = angle at 0*, 90*, etc. but
not in between. Problem is I don't know how to convert the linear index into
the appropriate angle. Any ideas?

Thanks a bunch,
Chris


----- Original Message ----- 
From: "Gary Fritz" <fritz@xxxxxxxx>
To: "omega List" <omega-list@xxxxxxxxxx>
Sent: Thursday, February 10, 2005 11:30 PM
Subject: Re: Can anyone help me fix my circle math?


> > Anyone see something that might be wrong?
> > value3=sine(idx*180);
> > if value3>0 then begin
> >   plot1(centerprice+radius*squareroot(value3));  //top half
> >   plot2(centerprice-radius*squareroot(value3));  //bottom half
> > end;
>
> Why are you taking the sqrt of the sine?  The Y offset of a
> circle is radius * sin(theta).
>
> Taking the sqrt of the sin should make for squarish circles,
> since sin(45deg) = 0.7071 and sqrt(sin(45deg)) is 0.8409.  See
> attached for an example.
>
> Gary
>
>

Attachment: solidus1.gif
Description: GIF image

Attachment: solidus0.gif
Description: GIF image