Using Circular Region as Input

[Sena_Scott]

Hi guys,

In a circular motion,my "t" value in a Cosine (x-axis) and Sine (y-axis) is a varying number, which keep increasing. I have a point on the perimeter of the circle, However, at the 4 different region from 0-90, 90-180, 180-270, 270-360, it will react different for me to obtain the center point of the circle. At region 0-90, my center is the (point of the circle) minus (x value calculated from the radius i fix) & the (y value calculated from the radius), Region 90-180, it will be +x value & - y value. The similar algorithm applies to region 3 and 4. Lastly, is there any function in LabView i could use to use the region i am in to perform a action required by me.

Regards,

Scott

[altenbach]

Your posts makes little sense to me. Can you attach a small VI or graphic that explains what you have and what you want?

If you just want to detect the current quadrant, there are many simple ways to do that.

What is your LabVIEW version?

[Bob_Schor]

It sounds to me that you are using the following equations for a point on a circle at time t:

   x(t) = x0 + r sin(omega*t)

   y(t) = y0 + r cos(omega*t)

where omega is the frequency that you are zipping around the circle.  If you know the (fixed) radius, r, and the frequency omega, then giving any pair of x, y points at a known value of t, it is trivial to unambiguously figure out x0 and y0 (it is basically a subtraction problem).  No need to worry about what quadrant you are in, just do the arithmetic.