API client for CAMS radiation service
Usage
cams_api(lat, lng, date_begin, date_end, alt = -999,
time_step = "PT01H", time_ref = "UT", verbose = FALSE,
service = "get_cams_radiation", format = "application/csv",
filename = "")Arguments
- lat
Latitude, in decimal degrees. Required
- lng
Longitude, in decimal degrees. Required
- date_begin
Start date as 'yyyy-mm-dd' string. Required
- date_end
End date as 'yyyy-mm-dd' string. Required
- alt
Altitude in meters, use -999 to let CAMS decide. Default -99
- time_step
Aggregation: 'PT01M' for minutes, 'PT15M' for 15 minutes, 'PT01H' for hourly, 'P01D' for daily, 'P01M' for monthly. Deafult 'PT01H'
- time_ref
Time reference:'UT' for universal time, 'TST' for true solar time. Default 'UT'
- verbose
TRUE for verbose output. Default "FALSE"
- service
'get_mcclear' for CAMS McClear data, 'get_cams_radiation' for CAMS radiation data. Default 'get_cams_radiation'
- format
'application/csv', 'application/json', 'application/x-netcdf' or 'text/csv'. Default 'application/csv'
- filename
path to file on disk to write to. If empty, data is kept in memory. Default empty
Value
list(ok=TRUE/FALSE, response=response). If ok=TRUE, response is the response from httr::GET. If ok=FALSE, response holds exception text
Examples
if (FALSE) { # \dontrun{
library(ncdf4)
filename <- paste0(tempfile(), ".nc")
# API call to CAMS
r <- cams_api(
60, 15, # latitude=60, longitude=15
"2016-06-01", "2016-06-10", # for 2016-06-01 to 2016-06-10
time_step="PT01H", # hourly data
service="get_cams_radiation", # CAMS radiation
format="application/x-netcdf",# netCDF format
filename=filename) # file to save to
# Access the on disk stored ncdf4 file
nc <- nc_open(filename)
# list names of available variables
names(nc$var)
# create data.frame with timestamp and global horizontal irradiation
df <- data.frame(datetime=as.POSIXct(nc$dim$time$vals, "UTC",
origin="1970-01-01"),
GHI = ncvar_get(nc, "GHI"))
plot(df, type="l")
nc_close(nc)
} # }