code_01_read_NetCDF_using_stars_package.R

library(stars)

## Loading required package: abind

## Loading required package: sf

## Linking to GEOS 3.5.1, GDAL 2.2.2, proj.4 4.9.2

setwd("/home/michael/Dropbox/BGU/Alex_Shtein/p_26_read_NetCDF_using_stars_package/")

# File path
file = "/media/qnap/Projects/P062.EU.PM/raw/ECMWF_aod/macc_2003_02.ncdf"

# Read & convert to data.frame
start = Sys.time()
r = read_stars(file)

## aod550,

## Warning: ignoring unrecognized unit: ~

## ssaod550,

## Warning: ignoring unrecognized unit: ~

## duaod550,

## Warning: ignoring unrecognized unit: ~

## omaod550,

## Warning: ignoring unrecognized unit: ~

## bcaod550,

## Warning: ignoring unrecognized unit: ~

## suaod550,

## Warning: ignoring unrecognized unit: ~

## aod469,

## Warning: ignoring unrecognized unit: ~

## aod670,

## Warning: ignoring unrecognized unit: ~

## aod865,

## Warning: ignoring unrecognized unit: ~

## aod1240,

## Warning: ignoring unrecognized unit: ~

dat = as.data.frame(r)
end = Sys.time()

# Timing
end-start

## Time difference of 34.64868 secs

# Resulting table
head(dat)

##         x    y                time    aod550  ssaod550    duaod550
## 1 -12.500 71.5 2003-02-01 03:00:00 0.2275700 0.2199241 0.001040657
## 2 -12.375 71.5 2003-02-01 03:00:00 0.2292932 0.2217974 0.001040657
## 3 -12.250 71.5 2003-02-01 03:00:00 0.2309957 0.2236508 0.001040657
## 4 -12.125 71.5 2003-02-01 03:00:00 0.2327190 0.2255242 0.001040657
## 5 -12.000 71.5 2003-02-01 03:00:00 0.2344215 0.2273776 0.001040657
## 6 -11.875 71.5 2003-02-01 03:00:00 0.2346291 0.2275968 0.001040657
##       omaod550     bcaod550    suaod550    aod469    aod670    aod865
## 1 0.0010112372 0.0009521578 0.004641726 0.2270672 0.2280333 0.2276666
## 2 0.0009949521 0.0009429965 0.004515903 0.2287580 0.2297980 0.2294954
## 3 0.0009786671 0.0009338352 0.004390079 0.2304240 0.2315628 0.2313446
## 4 0.0009623820 0.0009246740 0.004264256 0.2320899 0.2333275 0.2331735
## 5 0.0009460970 0.0009162174 0.004138433 0.2337807 0.2350720 0.2350226
## 6 0.0009428399 0.0009148080 0.004138433 0.2339797 0.2352748 0.2352055
##     aod1240
## 1 0.2245466
## 2 0.2264793
## 3 0.2284120
## 4 0.2303447
## 5 0.2322775
## 6 0.2324385