Karl,
You are using a default RasterLayer which has lon/lat coordinates. In
that case the earth is considered spherical (or similar), not a plane.
The maximum possible distance in longitude is 180 degrees, and the
distance between -120 and 120 is not 240 degrees, but 60+60= 120
degrees, .
To get
=uniqueFromCells, to=uniqueToCells, mode=out,
algorithm=dijkstra)
-Original Message-
From: R-sig-Geo [mailto:r-sig-geo-boun...@r-project.org] On Behalf Of karljarvis
Sent: Thursday, March 12, 2015 2:36 PM
To: r-sig-geo@r-project.org
Subject: [R-sig-Geo] gdistance: costDistance with barriers
Hi all,
I am seeing confusing behavior from the costDistance function in gdistance.
In general, when cost is constant, cost distance increases linearly with
actual distance. However, in this example, it is not doing that for the
longest few distances. Am I missing something?
Karl
r -
Apologies for the confusing subject line...
-
Karl Jarvis
--
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Robert is right. This example visualizes what is happening.
library(gdistance)r - raster(nrows=18, ncols=36) r[] - 1x -
transition(r,function(x) 1/mean(x),4)origin - c(-120,0)goal - c(120,0)sl -
shortestPath(x, origin, goal)plot(raster(sl))
On Thursday, 12 March 2015, 14:50, Robert J.
Great! Thank you all.
On Mar 12, 2015, at 4:35 PM, Jacob van Etten jacobvanet...@yahoo.com wrote:
Robert is right. This example visualizes what is happening.
library(gdistance)
r - raster(nrows=18, ncols=36)
r[] - 1
x - transition(r,function(x) 1/mean(x),4)
origin - c(-120,0)
goal -
