I am a beginner in R.
I am trying to download NetCDF4 files from the NASA subset wizzard (https://disc.gsfc.nasa.gov/SSW/#keywords=TRMM_3B42RT_Daily) - in my case, I am looking for TRMM 3B42 precipitation data for South Africa. I will need to download thousands of datasets and work with them in raster format in R and therefore want to use the URL's provided by the subset wizzard. e.g.:
http://disc2.gesdisc.eosdis.nasa.gov/opendap/TRMM_RT/TRMM_3B42RT_Daily.
7/2016/10/3B42RT_Daily.20161001.7.nc4.nc4?precipitation[777:867][99:173],
precipitation_cnt[777:867][99:173],uncal_precipitation_cnt[777:867][99:173],
lat[99:173],lon[777:867]
I have tried
url1 <- "http://.."
dest <- "C:\\Users\\User\\Documents\\3_UP\\2016_Masters\\
Dissertation\\Satellite Data\\TRMM Precipitation\\TRMM 3B42 Daily RT\\Try.nc4.nc4"
download.file(url=url1, destfile=name, mode="wb")
And here I receive an error message "cannot open URL" and additional Warning Messages ending with "HTTP status was '401 Unauthorized'.
Which led me to suspect that the browser needed some login details. In Chrome- the URL works as is. in Internet Explorer (R's default) I typed in my username and password once and after that - the URL also works as is.
However, no success with R functions. The errors remain. I have tried to use other R packages and functions - however, this is my first time trying something like this and I am not seeing the light yet. e.g. most RCurl functions see illegal characters found in the URL.
Does anyone have more experience in working with these specific files ?
best regards Marion
