Radius search

[Terrence Burke]

> You shouldn't need complicated math: good old Pythagoras is good enough for
> small distances (ie approximating to flat & not too much variation in the
> length of arc subtended by 1 degree East).
> 
> x*x + y*y = z*z
> 
> where x, y, z are the sides of a right-angled triangle.
> 
> Eg: x is the relative Easting, y is the relative Northing, then z will be the
> distance "as the crow flies".
> 
> There's no sqrt function either of course, but you could select all with
> z*z <= 10000, and put them in distance order.
> 
              But x^(0.5) is perfectly acceptably  --  the biggest problem
              now being that of scaling the numeric values to obtain the 
              required visual/printed output.

                           Terry Burke


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Terry Burke
Admin Information Systems           EMail T.E.Burke@Dundee.ac.uk
University of Dundee
Nethergate                          Phone 01382 344022
Dundee     DD1 4HN                    Fax 01382 201604
Scotland   UK.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Subscribe: "subscribe powerh-l" in message body to majordomo@lists.swau.edu
Unsubscribe: "unsubscribe powerh-l" in message to majordomo@lists.swau.edu
This list is closed, thus to post to the list, you must be a subscriber.