[R-sig-Geo] Vegetation calculation

2011-01-26 Thread Malik Shahzad
Dear Community! I need to calculate the total pixels of vegetation in my Quick bird Image. I want to divide image by 300*300 pixel and then want to know how many pixels are covered with vegetation within this area and so on for whole image. e.g. Area1= 45 pixel out of 300*300 pixels, Area2=

[R-sig-Geo] ECMWF grib and raster

2011-01-26 Thread bart
Hi All I'm trying to read grib files using Raster, form the ECMWF interim dataset (example file linked below). I don't get errors but the coordinate system of the read raster does not seem to match. raster(tmp.grib) class : RasterLayer filename: /home/bart/Desktop/tmp.grib nrow

Re: [R-sig-Geo] temperature interpolation -- was: 3D kriging with gstat

2011-01-26 Thread piero campa
This is more about kriging theory actually, but I can't understand in which different ways the elevation information is taken into account in the prediction process when e.g.: - I apply ordinary cokriging on input data which include 3D (x,y,h) spatial coordinates; - I apply universal cokriging

[R-sig-Geo] Problem with Kriging with in strata

2011-01-26 Thread Zia Ahmed
Hi, I am trying to do kriging with in strata. I use the example in book Applied Spatial Data Analysis with R page:217. It works fine with meuse data. But when I am trying to use my data it shows some error massage. Do I missing something here? Thanks in advance Zia Note: I am using

Re: [R-sig-Geo] Problem with Kriging with in strata

2011-01-26 Thread Edzer Pebesma
It seems your lt.a contains missing values. Try x1 - krige(sas ~ 1, tala[tala$lt.a == 0 !is.na(tala$lt.a), ], etc. On 01/26/2011 06:07 PM, Zia Ahmed wrote: Hi, I am trying to do kriging with in strata. I use the example in book Applied Spatial Data Analysis with R page:217. It works fine

Re: [R-sig-Geo] ECMWF grib and raster

2011-01-26 Thread Robert Hijmans
I'm trying to read grib files using Raster, form the ECMWF interim dataset (example file linked below). I don't get errors but the coordinate system of the read raster does not seem to match. Bart, I think this is due to an instance of the grid vs. cell-center convention mistake in gdal,