Terrence O'Neill wrote: > Thanks for sending me the code. I appreciate it. However, my situation is > a little more complicated than just 4 possibilities. My problem arrises > from having to create 90 arcs at a set distance away from a point, but at > varying angles. The problem I'm having is finding the MBR for that 90 > degree arc at any angle from 0 to 360 degrees.
You don't have enough information to solve that problem. All you know is one point's coordinates, and that the other point is 90 degrees from that along the perimeter of some ellipse, and the ellipse on which your arc is based is orthogonal to the XY axes, and that's not enough. You need the center of the ellipse or at least the angle that the known point makes to the center and the a and b distances (1/2 the x and y axes of the ellipse.) The formula for an ellipse (at the origin) is x^2/a^2 + y^2/b^2 = 1, where a and b are as described above. With only one point known, and its relation to the center unknown, you can draw any number of orthogonal ellipses through it and thus have any number of candidate points 90 degrees away. I'd say you need to also supply a center point at least. Since it doesn't seem to be critical to your app, just pick one arbitrarily such that the angle from it to your known point is one of those "varying angles", and the problem will then have only one solution instead of many. -- - Bill Thoen ------------------------------------------------------------ GISnet, 1401 Walnut St., Suite C, Boulder, CO 80302 tel: 303-786-9961, fax: 303-443-4856 mailto:[EMAIL PROTECTED], http://www.gisnet.com/ ------------------------------------------------------------ _______________________________________________________________________ List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MapInfo-L" in the message body.
