I was trying to solve this entirely within R -- this was my solution:
# The file is fixed width format, each number has a width of 5,
# with 36 numbers to a line:
soilwhc_dunne_raw_df <- read.fwf("soilwhc.dat",widths=rep(5,36))
soilwhc_dunne_raw_vector <- c(t(data.matrix(soilwhc_dunne_raw_df)))
soilwhc_dunne_raw_matrix <-
matrix(soilwhc_dunne_raw_vector,ncol=360,nrow=720)
# The image comes out flipped along the y axis:
soilwhc_dunne_raw <- flip(raster(t(soilwhc_dunne_raw_matrix)),"y")
extent(soilwhc_dunne_raw) <- extent(0,360,-90,90)
projection(soilwhc_dunne_raw) <- CRS("+proj=longlat +datum=WGS84")
# We'll also rotate it:
soilwhc_dunne_raw_rotate <- rotate(soilwhc_dunne_raw)
I was curious if there was a more elegant solution to this? Either way,
thanks for the response!
--j
On Fri, May 10, 2013 at 3:03 PM, Etienne B. Racine <[email protected]>wrote:
> Jonathan,
>
> You should set an header in the first file. Dunne_soil.dat is recognized
> as an Ascii Grid by GDAL because it has an header :
> ncols 720
> nrows 360
> xllcorner -180
> yllcorner -90
> cellsize 0.5
> NODATA_value -9999
>
> soilwhc.dat has no header. Also NA is coded with no space (-99.0-99.0).
> Maybe if you search and replace -99.0 by -9999[space] this would make it
> more standard. The lines are also rather short (36), but very long (7200).
> I guess each row is indeed 10 lines. It would share the same header than
> dunne_soil.dat. So you have some reformatting to get it working.
>
> Etienne
>
>
> 2013/5/10 Jonathan Greenberg <[email protected]>
>
>> r-sig-geo'ers:
>>
>> I'm trying some random hacks, but was wondering if there is a more
>> efficient way to import the following file:
>> ftp://ftp.daac.ornl.gov/data/global_soil/Dunne/data/soilwhc.dat
>>
>> as a raster(). The file is a fixed width file (width=5) of floating point
>> values, but had the Arc header stripped off. A reference file that DOES
>> work with raster is:
>>
>> ftp://ftp.daac.ornl.gov/data/global_soil/Dunne/data/dunne_soil.dat
>> reference_raster <- raster(dunne_soil.dat)
>> # This has the same number of rows and columns and resolution as
>> # the file above.
>>
>> Thoughts on the most efficient way to convert the first file to a workable
>> raster?
>>
>> --j
>>
>> --
>> Jonathan A. Greenberg, PhD
>> Assistant Professor
>> Global Environmental Analysis and Remote Sensing (GEARS) Laboratory
>> Department of Geography and Geographic Information Science
>> University of Illinois at Urbana-Champaign
>> 607 South Mathews Avenue, MC 150
>> Urbana, IL 61801
>> Phone: 217-300-1924
>> http://www.geog.illinois.edu/~jgrn/
>> AIM: jgrn307, MSN: [email protected], Gchat: jgrn307, Skype: jgrn3007
>>
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>>
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>>
>
>
--
Jonathan A. Greenberg, PhD
Assistant Professor
Global Environmental Analysis and Remote Sensing (GEARS) Laboratory
Department of Geography and Geographic Information Science
University of Illinois at Urbana-Champaign
607 South Mathews Avenue, MC 150
Urbana, IL 61801
Phone: 217-300-1924
http://www.geog.illinois.edu/~jgrn/
AIM: jgrn307, MSN: [email protected], Gchat: jgrn307, Skype: jgrn3007
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