-----Original Message-----
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org]
On Behalf Of Frede Aakmann Tøgersen
Sent: 16. april 2014 12:11
To: Bea GD; r-help@r-project.org
Subject: Re: [R] netCDF to raster and spatial projection
Well no need to have your data. Usually one can find some suitable data in
the help for the functions under question. So here is a reproducible example
from ?meuse.grid.
data(meuse.grid)
coordinates(meuse.grid) <- ~x+y
proj4string(meuse.grid) <- CRS("+init=epsg:28992") # see ?meuse for this
crs
gridded(meuse.grid) <- TRUE
summary(meuse.grid)
Object of class SpatialPixelsDataFrame
Coordinates:
min max
x 178440 181560
y 329600 333760
Is projected: TRUE
proj4string :
[+init=epsg:28992 +proj=sterea +lat_0=52.15616055555555
+lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000
+ellps=bessel +units=m +no_defs]
Number of points: 3103
Grid attributes:
cellcentre.offset cellsize cells.dim
x 178460 40 78
y 329620 40 104
Data attributes:
part.a part.b dist soil ffreq
Min. :0.0000 Min. :0.0000 Min. :0.0000 1:1665 1: 779
1st Qu.:0.0000 1st Qu.:0.0000 1st Qu.:0.1193 2:1084 2:1335
Median :0.0000 Median :1.0000 Median :0.2715 3: 354 3: 989
Mean :0.3986 Mean :0.6014 Mean :0.2971
3rd Qu.:1.0000 3rd Qu.:1.0000 3rd Qu.:0.4402
Max. :1.0000 Max. :1.0000 Max. :0.9926
rasterMG <- raster(meuse.grid)
print(rasterMG)
class : RasterLayer
dimensions : 104, 78, 8112 (nrow, ncol, ncell)
resolution : 40, 40 (x, y)
extent : 178440, 181560, 329600, 333760 (xmin, xmax, ymin, ymax)
coord. ref. : +init=epsg:28992 +proj=sterea +lat_0=52.15616055555555
+lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000
+ellps=bessel +units=m +no_defs
data source : in memory
names : part.a
values : 0, 1 (min, max)
rasterMG.proj <- spTransform(rasterMG, CRS("+init=epsg:21781"))
Error in spTransform(rasterMG, CRS("+init=epsg:21781")) :
load package rgdal for spTransform methods
Now perhaps doing the projection before casting it to a raster will work (yes
I'm guessing since error thrown above is not very informative and traceback()
does not give anything useful).
meuse.grid.proj <- spTransform(meuse.grid, CRS("+init=epsg:21781"))
Warning message:
In spTransform(meuse.grid, CRS("+init=epsg:21781")) :
Grid warping not available, coercing to points
summary(meuse.grid.proj)
Object of class SpatialPointsDataFrame
Coordinates:
min max
x 479029.8 482197.1
y 646927.4 651003.9
Is projected: TRUE
proj4string :
[+init=epsg:21781 +proj=somerc +lat_0=46.95240555555556
+lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel
+towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs]
Number of points: 3103
Data attributes:
part.a part.b dist soil ffreq
Min. :0.0000 Min. :0.0000 Min. :0.0000 1:1665 1: 779
1st Qu.:0.0000 1st Qu.:0.0000 1st Qu.:0.1193 2:1084 2:1335
Median :0.0000 Median :1.0000 Median :0.2715 3: 354 3: 989
Mean :0.3986 Mean :0.6014 Mean :0.2971
3rd Qu.:1.0000 3rd Qu.:1.0000 3rd Qu.:0.4402
Max. :1.0000 Max. :1.0000 Max. :0.9926
gridded(meuse.grid.proj) <- TRUE
suggested tolerance minimum: 0.737332
Error in points2grid(points, tolerance, round) :
dimension 1 : coordinate intervals are not constant
A warning and an error indicates that the projection results in something that
is not on a regular grid.
I don't know what to do but to read some more of the documentation for sp,
rgdal, etc.
Hopefully somebody comes up with something that helps us.
Yours sincerely / Med venlig hilsen
Frede Aakmann Tøgersen
Specialist, M.Sc., Ph.D.
Plant Performance & Modeling
Technology & Service Solutions
T +45 9730 5135
M +45 2547 6050
fr...@vestas.com<mailto:fr...@vestas.com>
http://www.vestas.com<http://www.vestas.com/>
Company reg. name: Vestas Wind Systems A/S
This e-mail is subject to our e-mail disclaimer statement.
Please refer to
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From: Bea GD [mailto:aguitatie...@hotmail.com]
Sent: 16. april 2014 11:00
To: Frede Aakmann Tøgersen; r-help@r-project.org
Subject: Re: [R] netCDF to raster and spatial projection
Hi Frede,
Thanks so much for your reply!
I've tried what you said but I get the following error:
Error in spTransform(rasterDF1, crs("+init=epsg:21781")) :
load package rgdal for spTransform methods
I've checked search() and rgdal is before sp.
search()
[1] ".GlobalEnv" "package:chron" "package:sm"
"package:rgeos"
[5] "package:maptools" "package:ncdf" "package:rgdal"
"package:raster"
[9] "package:sp" "tools:rstudio" "package:stats"
"package:graphics"
[13] "package:grDevices" "package:utils" "package:datasets"
"package:methods"
[17] "Autoloads" "package:base"
Also, when I do library("rgdal") I get this message:
library("rgdal")
rgdal: version: 0.8-16, (SVN revision 498)
Geospatial Data Abstraction Library extensions to R successfully loaded
Loaded GDAL runtime: GDAL 1.10.1, released 2013/08/26
Path to GDAL shared files: C:/Users/bgonzale/Documents/R/win-
library/3.0/rgdal/gdal
GDAL does not use iconv for recoding strings.
Loaded PROJ.4 runtime: Rel. 4.8.0, 6 March 2012, [PJ_VERSION: 480]
Path to PROJ.4 shared files: C:/Users/bgonzale/Documents/R/win-
library/3.0/rgdal/proj
Maybe the problem is something to do with this? I don't know how to fix it.
I'd like to provide you with some data, how would be the best way to
post/sahre a raster?
Thanks!
On 16.04.2014 10:17, Frede Aakmann Tøgersen wrote:
Hi Beatriz
Try to skip this step
# Reprojecting into CH1903_LV03
# First, change the coordinate reference system (crs)
proj4string(rasterDF1) <- "+init=epsg:21781"
And just do this
# Second, reproject the raster
rasterDF1.CH <- spTransform(rasterDF1, crs("+init=epsg:21781"))
Also there is a spTransform both in the rgdal and sp packages. So are they
masking each other? rgdal should be before sp in the search() list.
I cannot be of more help since you provided no data.
Yours sincerely / Med venlig hilsen
Frede Aakmann Tøgersen
Specialist, M.Sc., Ph.D.
Plant Performance & Modeling
Technology & Service Solutions
T +45 9730 5135
M +45 2547 6050
fr...@vestas.com<mailto:fr...@vestas.com>
http://www.vestas.com
Company reg. name: Vestas Wind Systems A/S
This e-mail is subject to our e-mail disclaimer statement.
Please refer to
www.vestas.com/legal/notice<http://www.vestas.com/legal/notice>
If you have received this e-mail in error please contact the sender.
-----Original Message-----
From: r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org>
[mailto:r-help-boun...@r-project.org]
On Behalf Of Beatriz R. Gonzalez Dominguez
Sent: 16. april 2014 08:22
To: r-help@r-project.org<mailto:r-help@r-project.org>
Subject: [R] netCDF to raster and spatial projection
I've recently started using R for spatial data. I'd be really grateful
if you could could help me with this. Thanks!
Sorry I don't provide a reproducible example. Please ask me if you have
any questions about the data.
I've extracted data from a multidimensional netCDF file. This file had
longitude, latitude and temperature data (for 12 months of a specific year).
From this netCDF I've got a data frame for January with these
variables: longitude, latitude, temperature.
With this data frame I've created a raster.
# Packages
library("sp")
library("raster")
library("rgdal")
library("ncdf")
library("maptools")
library("rgeos")
library("sm")
library("chron")
# Dataframe to raster
# Create spatial points data frame
coordinates(tmp.df01) <- ~ lon + lat
# Coerce to SpatialPixelsDataFrame
gridded(tmp.df01) <- T
# Coerce to raster
rasterDF1 <- raster(tmp.df01)
> print(tmp.df01)
class : SpatialPixelsDataFrame
dimensions : 103, 241, 24823, 1 (nrow, ncol, npixels, nlayers)
resolution : 0.02083333, 0.02083333 (x, y)
extent : 5.739583, 10.76042, 45.73958, 47.88542 (xmin, xmax,
ymin, ymax)
coord. ref. : NA
names : TabsM_1
min values : -18.1389980316162
max values : 2.26920962333679
There is no value for 'coord. ref.'
The projection of the original netCDF was WGS84. So I gave this
projection to the raster.
proj4string(rasterDF1) <- "+proj=longlat +datum=WGS84 +ellps=WGS84
+towgs84=0,0,0"
Then, I wanted to reproject my raster to another projection:
# Reprojecting into CH1903_LV03
# First, change the coordinate reference system (crs)
proj4string(rasterDF1) <- "+init=epsg:21781"
# Second, reproject the raster
rasterDF1.CH <- spTransform(rasterDF1, crs("+init=epsg:21781"))
At this point I get the following error:
Error in spTransform(rasterDF1, crs("+init=epsg:21781")) :
load package rgdal for spTransform methods
But the package rgdal is already uploaded! It must be something wrong in
the code!
______________________________________________
R-help@r-project.org<mailto:R-help@r-project.org> mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-
guide.html
and provide commented, minimal, self-contained, reproducible code.
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