externalrdata

This package is a template R package to fetch, cache, and serve data from external sources. All data sources are assumed to be csv files. The typical workflow would be to fork this package and rename the project-specific pieces including:

• temp_get
  • baseurl
  • files
• cache_path
  • appname
  • appauthor
• function prefixes (e.g. change temp_get to myspecificproject_get)

Installation

# install devtools if not found
# install.packages(devtools)
devtools::install_github("jsta/externalrdata")

Usage

library(externalrdata)

Download external data and store in file system

# for demonstration purposes we will set on-the-fly compilation to FALSE
temp_get(version_id = "1", compile = FALSE)

List files

temp_ls(version_id = "1")
#> [1] "rows.csv"

Compile version

# these files have metadata headers that need to be skipped
temp_compile(version_id = "1", skip = c(16, 38))
#> data compiled to /home/jose/.local/share/externalrdata//data_1.rds

List versions

temp_versions()
#> [1] "1"

Load data

dt <- temp_load(version_id = "1")
names(dt)
#> [1] "rows"
lapply(dt, head)
#> $rows
#>   S.MARTIN.LUTHER.KING.JR.BLVD...W.PRATT.ST S.B  MLK.Jr..Blvd..
#> 1                ORLEANS ST & N LINWOOD AVE E/B         Orleans
#> 2          E NORTHERN PKWY & SPRINGLAKE WAY W/B Northern Pkwy\n
#> 3             W COLD SPRING LN & ROLAND AVE E/B   Cold Spring\n
#> 4                 E NORTHERN PKWY & YORK RD W/B Northern Pkwy\n
#> 5                 N CHARLES ST & E LAKE AVE S/B         Charles
#> 6               W FAYETTE ST & N LIBERTY ST W/B       Fayette\n
#>              Pratt.St         MLK.Jr..Blvd.....Pratt.St
#> 1         Linwood Ave           Orleans   & Linwood Ave
#> 2      Springlake Way Northern Pkwy\n  & Springlake Way
#> 3          Roland Ave       Cold Spring\n  & Roland Ave
#> 4           York Road      Northern Pkwy\n  & York Road
#> 5            Lake Ave                Charles & Lake Ave
#> 6 Liberty Heights Ave  Fayette\n  & Liberty Heights Ave
#>   X.39.286027...76.627846. X11 X168 X27953
#> 1  (39.295866, -76.576427) 141  123  27935
#> 2  (39.364311, -76.617699) 116  271  14009
#> 3  (39.343906, -76.635426) 214  236  14004
#> 4  (39.365146, -76.609922) 132  257  14009
#> 5  (39.369054, -76.625827) 235  272  14009
#> 6  (39.290504, -76.617661)  65    6  13642

Examples

Uses this template

• https://github.com/jsta/nesRdata
• https://github.com/jsta/nsws

Uses as similar strategy

• https://github.com/jsta/nhdR

Contributing

Contributions welcome in the form of issues and pull requests.