astropic

The goal of astropic is to connect R to the NASA APOD API. The APOD API supports one image at a time. In order to supply more than that, this package also includes creating time ranges (of less than 1000 days at a time) and some historical data in tibble format.

Thanks to Michael W. Kearney, author of rtweet, for having a robust package based on connecting to an API. I didn’t know much about APIs when I started this project and looking at his source code helped a ton!

Installation

You can install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("eringrand/astropic")

API Key

To start, you’ll need a NASA API key. If you do not have one, you can get one here. Once you put in your information, a key will be emailed to you.

Save this to your environment as NASA_KEY. e.g Sys.setenv(NASA_KEY = "YOURKEYHERE").

Query

The query parameters are described on the APOD API Github page as such…

• date A string in YYYY-MM-DD format indicating the date of the APOD image (example: 2014-11-03). Defaults to today’s date. Must be after 1995-06-16, the first day an APOD picture was posted. There are no images for tomorrow available through this API.
• hd A Boolean parameter indicating whether or not high-resolution images should be returned. This is present for legacy purposes, it is always ignored by the service and high-resolution urls are returned regardless.
• count A positive integer, no greater than 100. If this is specified then count randomly chosen images will be returned in a JSON array. Cannot be used in conjunction with date or start_date and end_date.
• start_date A string in YYYY-MM-DD format indicating the start of a date range. All images in the range from start_date to end_date will be returned in a JSON array. Cannot be used with date.
• end_date A string in YYYY-MM-DD format indicating that end of a date range. If start_date is specified without an end_date then end_date defaults to the current date.

Example

This is a basic example to retrieve APOD data.

Basic Example

library(astropic)
get_apod() # no inputs will get today's image
#> # A tibble: 1 x 7
#>   date   explanation    hdurl    media_type service_version title  url     
#>   <chr>  <chr>          <chr>    <chr>      <chr>           <chr>  <chr>   
#> 1 2019-… How far away … https:/… image      v1              Anemi… https:/…

Providing a date range

You can also supply a start and end date to get a range of image results back.

get_apod(query  = list(start_date = "2018-04-01", end_date = "2018-04-03"))
#> # A tibble: 3 x 8
#>   copyright  date  explanation hdurl media_type service_version title url  
#>   <chr>      <chr> <chr>       <chr> <chr>      <chr>           <chr> <chr>
#> 1 Fernando … 2018… I love you… http… image      v1              I Br… http…
#> 2 <NA>       2018… While crui… http… image      v1              Moon… http…
#> 3 Sergei Ma… 2018… You may ha… http… image      v1              The … http…

Count - n random images

get_apod(query = list(count = 5))
#> # A tibble: 5 x 8
#>   date   explanation hdurl media_type service_version title url   copyright
#>   <chr>  <chr>       <chr> <chr>      <chr>           <chr> <chr> <chr>    
#> 1 1995-… August 11,… http… image      v1              The … http… <NA>     
#> 2 1999-… It's 2 AM … http… image      v1              Ther… http… <NA>     
#> 3 2008-… What if yo… <NA>  video      v1              Fire… http… Global T…
#> 4 2010-… After an o… http… image      v1              Dama… http… <NA>     
#> 5 1999-… In astrono… http… image      v1              A Su… http… <NA>

Magic

With a little magick you can also save the APOD image to your computer for use later. This is a demonstration of a picture in APOD I helped to create!

library(magick)
library(here)
library(dplyr)

save_image <- function(url){
  image <- try(magick::image_read(url), silent = FALSE)
  image_name <- gsub(".*/([^/]+$)", '\\1', m31$hdurl)
  image_loc <- here::here("man/figures/README", image_name)
  if(class(image)[1] != "try-error"){
    image %>%
    magick::image_write(image_loc)
  }
  return(image)
}

m31 <- get_apod(query = list(date = "2009-09-17"))  # only providing a start date will give the image just for that day
dplyr::pull(m31, explanation)
#> [1] "Taken by a telescope onboard NASA's Swift satellite, this stunning vista represents the highest resolution image ever made of the Andromeda Galaxy (aka M31) - at ultraviolet wavelengths. The mosaic is composed of 330 individual images covering a region 200,000 light-years wide. It shows about 20,000 sources, dominated by hot, young stars and dense star clusters that radiate strongly in energetic ultraviolet light. Of course, the Andromeda Galaxy is the closest large spiral galaxy to our own Milky Way, at a distance of some 2.5 million light-years. To compare this gorgeous island universe's appearance in optical light with its ultraviolet portrait, just slide your cursor over the image.   digg_url ='http://apod.nasa.gov/apod/ap090917.html'; digg_skin = 'compact';"
save_image(m31$hdurl)

Contact

Come find me on twitter @astroeringand

Code of Conduct

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.