Is there an annotated river dataset available?
On Fri, 8 Jan 2010 10:11:20 +0100 Hans-J?rg Bibiko <bibiko at eva.mpg.de> wrote:
I've a tiny question. Is there an annotated river dataset available? By 'annotated' I mean that rivers are ranked by a sort of relevance/size/length or whatever. The problem is that I have an huge SpatialLines object called 'rivers' which shows ~23200 rivers but I have to draw a map which only shows the most largest ones (let's say 100 to 150) plus one to three rivers for a country.
How about using the 'SpatialLinesLengths' function? Try get the 100 largest rivers, you can use big.rivers=rivers[rev(order(SpatialLineLengths(rivers)))[1:100],] 'SpatialLinesLengths' may have a bug, though. At least for one of my data, it gives a 'non-finite line lengths' error message on one of the (finite!) lines.
Karl Ove Hufthammer