newkirk@hao.UUCP (07/10/84)
What is desired is, given a regular function z(x,y) specified at uniform grid points in x and y, to locate the ridge lines in z with a specified spatial resolution. To put it into a geographical term, one wants a program to find the continental divide on a contour map. Examination of the problem shows that such "divides" are a special set of the flow lines which are always normal to the contour lines. Their special characteristic is that a divide connects peaks through a saddle point. I have tried at our local sources, the USGS, etc. without success although there do exist some of the components which could be put together a program to do this job. Any ideas as to how to locate if one already exists? Please reply by mail as I do not normally read news. Thanks, Gordon Newkirk hao!newkirk