SpatialPixelsDataFrame() tries to figure out how the points you feed it
with are layed out on a grid structure. Small errors, possibly from
rounding (you're reading from ascii) may cause it to go slightly wrong,
and not give you the grid you'd like.
As you probably know the grid at which "coords.txt" is layed out, you
can create it the right way and pass it to SpatialPixelsDataFrame(). Use
function GridTopology() for this.
On 02/06/2013 10:45 AM, fsan...@ujaen.es wrote:
Dear R-Geo users,
I am trying to create a SP objects using SpatialPixelsDataFrame. Next I
can see the code:
proj <- '+proj=lcc +ellps=WGS84 +lat_0=0 +lat_1=30 +lat_2=60 +lon_0=-4.75'
coords <- read.table("coords.txt")
dat <- read.table("dem.txt")
test <- SpatialPixelsDataFrame(points=coords, data=dat, proj4string=proj)
Error in if (max(object@grid.index) > .NumberOfCells(object@grid))
stop("grid.index max value too large") :
missing value where TRUE/FALSE needed
In addition: Warning messages:
1: In points2grid(points, tolerance, round) :
grid has empty column/rows in dimension 1
2: In points2grid(points, tolerance, round) :
grid topology may be corrupt in dimension 1
3: In points2grid(points, tolerance, round) :
grid has empty column/rows in dimension 2
4: In points2grid(points, tolerance, round) :
grid topology may be corrupt in dimension 2
5: In getGridIndex(coordinates(points), grid) : NAs introduced by coercion
What's the problem?
PD: I can not attach data for this because the size exceeds the maximum
allowable.
Thanks in advance.
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Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de
http://www.52north.org/geostatistics e.pebe...@wwu.de
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