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Topic: Some help with a project please
Replies: 0

 Peter Nolan Posts: 1 Registered: 12/8/04
Some help with a project please
Posted: Jul 29, 1999 4:44 AM

Hi guys,

I have a problem that appears to be waaaaaaaaay beyond my math
capability and would appreciate a little help.

I need to describe an arc using just two sets of coordinates from a
known start-point. These coordinates can be positive or negative and
in any practical combination. They will be relative to the start point
which can be anywhere.

Y+
|
| X=0, Y=0 is at the intersection.
| Going North/Up is Y-positive and
-X------+------X+ East/Right is X-positive. The other
| coordinates are defined as I and J
| and they represent the same
| as X and Y respectively.
-Y

Ok, now for an arc or two.

Start point X-138, Y+10

CW arc X-160, Y+17, I+0, J+35

I am already at a start-point of X=-138, Y=10 then I am given the
coordinates for a CW arc. The arc is to end at X=-160, and Y=17 with
the center of the arc at I=0 (actually X=0) and J=35 (actually Y=35)

Now with the start point for a CCW arc being the end point of the
previous arc, I need to draw another curve to make an S-shape
following on from the first arc.

CCW arc X-163, Y+16, I-1, J-1

The CCW need not have started at the end of the first one, as I could
have moved to another start point first, before drawing the CCW arc. I
just used this as an example, but in real life the arcs can be
anywhere and need not follow on.

Do I need a different formula for CW and CCW?

I'd appreciate some enlightenment here as it all looks like spaghetti
to me.

--

Regards,

Peter Nolan
CEO Nolan Innovation Inc.
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