[R-sig-Geo] raster pkg: overwriting the dimensions detected by netcdf4 (PERSIANN-CDR)

MAURICIO ZAMBRANO BIGIARINI mauricio.zambrano at ufrontera.cl
Wed Feb 3 15:26:05 CET 2016


Dear spatial community,

While reading some netCDFfiles with the raster package , I got a
"rotated" file, where the columns where read as rows and vice versa:

------------- START ----------------
x <- raster("PERSIANN-CDR_v01r01_20090101_c20140523.nc")
Loading required namespace: ncdf4
plot(x)
x
class       : RasterLayer
dimensions  : 1440, 480, 691200  (nrow, ncol, ncell)
resolution  : 0.25, 0.25  (x, y)
extent      : -60, 60, 0, 360  (xmin, xmax, ymin, ymax)
coord. ref. : NA
data source : /home/hzambran/PERSIANN-CDR_v01r01_20090101_c20140523.nc
names       : NOAA.Climate.Data.Record.of.PERSIANN.CDR.daily.precipitation
z-value     : 2009-01-01
zvar        : precipitation
------------- END ----------------

The previous summary shows that the spatial extent of the file is
60W-60E and 0-360N, while the correct extent should be: 60S, 60N, 0E,
360E.

The file can be downloaded from:
ftp://data.ncdc.noaa.gov/cdr/persiann/files/2009/PERSIANN-CDR_v01r01_20090101_c20140523.nc


After contacting the providers of the file, they mentioned that when
reading the file I have to provide the dimension information, i.e.,
480 rows and 1440 columns, while the raster package detects the other
way around.

I would highly appreciate if you could tell me:

1) is the previous situation a bug of my netCDF driver (netCDF 4.1.3,
GDAL 1.11.2, released 2015/02/10) or a problem of the dimensions
actually recorded in the netCDF file ?

2) is there any way to  overwrite the dimensions detected by netcdf4
when reading the file with the 'raster' command ?


My sessionInfo():
R version 3.2.3 (2015-12-10)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 14.04.2 LTS

locale:
 [1] LC_CTYPE=en_GB.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_GB.UTF-8        LC_COLLATE=en_GB.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_GB.UTF-8
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] raster_2.5-2 sp_1.2-1

loaded via a namespace (and not attached):
[1] tools_3.2.3     Rcpp_0.12.3     ncdf4_1.15      grid_3.2.3
[5] lattice_0.20-33


Thanks in advance and kind regards

Mauricio Zambrano-Bigiarini, PhD

=====================================
Dept. of Civil Engineering
Faculty of Engineering and Sciences
Universidad de La Frontera
PO Box 54-D, Temuco, Chile
http://ingenieriacivil.ufro.cl/
=====================================
mailto     : mauricio.zambrano at ufrontera.cl
work-phone : +56 45 259 2812
=====================================
"In the end, it's not the years in your life that count.
 It's the life in your years". (Abraham Lincoln)
=====================================
Linux user #454569 -- Linux Mint user

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