Re: [R-sig-Geo] Problem Setting Projection of Rasters upon Import

Roger Bivand Fri, 12 Jul 2013 01:01:37 -0700

On Fri, 12 Jul 2013, Michael Treglia wrote:

Thanks for trying Erin!
I appreciate knowing its not just me :-)

Are your raster package versions different? In current raster,R/rasterFromGDAL.R in line 129 sets crs="", and because in line 152 theassigned value in:


projection(r) <- attr(gdalinfo, 'projection')

is NA, you get what you see. My guess is that if your crs= argument isneither missing nor NA or the empty string, it should poverrideattr(gdalinfo, 'projection').

Providing the version of your older installation of raster will helpisolate when and which change has led to this outcome, but you do have aworkaround. I can't see the offending revision in SCM in R-forge.


Roger

-Mike


On Thu, Jul 11, 2013 at 6:40 PM, Hodgess, Erin <hodge...@uhd.edu> wrote:

 Hi again.

It looks like the crs argument no longer works when creating a raster from
a file.  I've tried all kinds of "variations on the theme" also, but no
luck.

Weird.

Thanks
Erin

 ------------------------------
*From:* Michael Treglia [mtreg...@gmail.com]
*Sent:* Thursday, July 11, 2013 8:21 PM
*To:* Michael Sumner
*Cc:* Hodgess, Erin; r-sig-geo@r-project.org
*Subject:* Re: [R-sig-Geo] Problem Setting Projection of Rasters upon
Import

   Hi,
 I apologize - I must have mistakenly copied/pasted only the last "t"

 Here is how it was run, and the results, in R 3.0.0 (64-bit):

test<-raster("us_ppt_1981_2010.02.asc", crs="+proj=longlat +ellps=GRS80")
test

class       : RasterLayer
dimensions  : 3105, 7025, 21812625  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : -125.0208, -66.47917, 24.0625, 49.9375  (xmin, xmax, ymin,
ymax)
coord. ref. : NA
data source : D:\GIS\PRISM\1981-2010\PPT\us_ppt_1981_2010.02.asc
names       : us_ppt_1981_2010.02
values      : -2147483648, 2147483647  (min, max)


 and in R 2.13.0 (also 64-bit):

test<-raster("us_ppt_1981_2010.02.asc", crs="+proj=longlat +ellps=GRS80")
test

class       : RasterLayer
dimensions  : 3105, 7025, 21812625  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : -125.0208, -66.47917, 24.0625, 49.9375  (xmin, xmax, ymin,
ymax)
coord. ref. : +proj=longlat +ellps=GRS80
values      : D:\GIS\PRISM\1981-2010\PPT\us_ppt_1981_2010.02.asc




On Thu, Jul 11, 2013 at 6:13 PM, Michael Sumner <mdsum...@gmail.com>wrote:

Please report on the actual code you ran, you've just sent two
messages, one with

test<-raster("us_ppt_1981_2010.02.asc", crs="+ellps=GRS80")

 this correctly cannot set the CRS and so it is NA

and the other with

t<-raster("us_ppt_1981_2010.02.asc", crs="+proj=longlat +ellps=GRS80")

test


 We have no idea what you see in "t" now. In short you have to have a
"+proj", not just a "+ellps" for this incantation. You can check with

library(rgdal)
CRS("+ellps=GRS80")
Error in CRS("+ellps=GRS80") : projection not named






On Fri, Jul 12, 2013 at 11:10 AM, Michael Treglia <mtreg...@gmail.com>
wrote:

I just tried running it in an older version of R, 2.13.0 (64-bit) and it
ran with no problem... the exact same code run from Notepad++

Anybody know what has changed/if I need to adjust my for R 3.x.x?

t<-raster("us_ppt_1981_2010.02.asc", crs="+proj=longlat +ellps=GRS80")

test

class       : RasterLayer
dimensions  : 3105, 7025, 21812625  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : -125.0208, -66.47917, 24.0625, 49.9375  (xmin, xmax, ymin,
ymax)
coord. ref. : +proj=longlat +ellps=GRS80
values      : D:\GIS\PRISM\1981-2010\PPT\us_ppt_1981_2010.02.asc

Thanks again!
Mike


On Thu, Jul 11, 2013 at 5:59 PM, Michael Treglia <mtreg...@gmail.com>

wrote:

Hi Erin,

Thanks for the quick response - I did try it with the plus sign, and

same

result. (I also tried it with 'crs="+proj=longlat +ellps=GRS80"' with

the

same result too.)

 test<-raster("us_ppt_1981_2010.02.asc", crs="+ellps=GRS80")
 test

class       : RasterLayer
dimensions  : 3105, 7025, 21812625  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : -125.0208, -66.47917, 24.0625, 49.9375  (xmin, xmax,

ymin,

ymax)
coord. ref. : NA
data source : D:\GIS\PRISM\1981-2010\PPT\us_ppt_1981_2010.02.asc
names       : us_ppt_1981_2010.02
values      : -2147483648, 2147483647  (min, max)

I'm running R Version 3.0.0, 64-bit, in case that helps at all...
Cheers,
Mike


On Thu, Jul 11, 2013 at 5:50 PM, Hodgess, Erin <hodge...@uhd.edu>

wrote:

Hi Michael:

Did you try this;

test<-raster("us_ppt_1981_2010.02.asc", crs="+ellps=GRS80")

with the plus sign, please?

That might do it.

Thanks,
Erin

________________________________________
From: r-sig-geo-boun...@r-project.org [

r-sig-geo-boun...@r-project.org]

on behalf of Michael Treglia [mtreg...@gmail.com]
Sent: Thursday, July 11, 2013 7:16 PM
To: r-sig-geo@r-project.org
Subject: [R-sig-Geo] Problem Setting Projection of Rasters upon Import

Hi All,

I am using he "raster" package, and in particular the "raster"

function. I

am dealing with a number of layers, and it would be easiest to set

the CRS

upon import. Looking through the documentation, it seems that it is
doable,
and I have been using the following code to get started, though it is

not

setting the CRS.

Here are my code, and the results of the import:

test<-raster("us_ppt_1981_2010.02.asc", crs="ellps=GRS80")
test

class       : RasterLayer
dimensions  : 3105, 7025, 21812625  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : -125.0208, -66.47917, 24.0625, 49.9375  (xmin, xmax,

ymin,

ymax)
*coord. ref. : NA *
data source : D:\GIS\PRISM\1981-2010\PPT\us_ppt_1981_2010.02.asc
names       : us_ppt_1981_2010.02
values      : -2147483648, 2147483647  (min, max)

If I use the "projection" command afterwards, it sets the projection
appropriately though.

projection(test)<-CRS("+proj=longlat +ellps=GRS80")
test

class       : RasterLayer
dimensions  : 3105, 7025, 21812625  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : -125.0208, -66.47917, 24.0625, 49.9375  (xmin, xmax,

ymin,

ymax)
*coord. ref. : +proj=longlat +ellps=GRS80 *
data source : D:\GIS\PRISM\1981-2010\PPT\us_ppt_1981_2010.02.asc
names       : us_ppt_1981_2010.02
values      : -2147483648, 2147483647  (min, max)

Any suggestions of why the first option is not working? I have a

script in

which I import all files in a folder, and the simplest way to assign

the

projection would be the first option (I'm using an 'lapply' command).
It would look something like this:
import <- lapply(filenames ,raster, crs="....") #where "filenames" is

vector of filenames in the working directory.

In case it helps, these are PRISM Climate Data, and the header of my
raster
file is this:
ncols 7025
nrows 3105
xllcorner -125.020833333333329
yllcorner 24.062500000000000
cellsize 0.008333333333333
NODATA_value -9999

Thanks for any suggestions!
Mike

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 --
Michael Sumner
Hobart, Australia
e-mail: mdsum...@gmail.com


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--
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: roger.biv...@nhh.no

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Re: [R-sig-Geo] Problem Setting Projection of Rasters upon Import

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