EPA Fuel Economy Data (Racket Usage)

Note: Code output provided for programs run in “Intermediate Student” language, but code should also run in #lang racket similarly.

Contents

Source

http://www.fueleconomy.gov/feg/ws/index.shtml

Data services

Fuel prices

Code

(require sinbad)

(fetch
 (sail-to "http://www.fueleconomy.gov/ws/rest/fuelprices"
          (format "xml") (load) (manifest)))

(fetch
 (sail-to "http://www.fueleconomy.gov/ws/rest/fuelprices"
          (format "xml") (load))
 "premium")  ; select only "premium" field data

Output

The following data is available:
structure with {
  cng : *
  diesel : *
  e85 : *
  electric : *
  lpg : *
  midgrade : *
  premium : *
  regular : *
}

(list
 (cons "cng" 2.15)
 (cons "diesel" 2.78)
 (cons "e85" 1.99)
 (cons "electric" 0.13)
 (cons "lpg" 2.84)
 (cons "midgrade" 2.78)
 (cons "premium" 3.03)
 (cons "regular" 2.5))
3.03

All Vehicle Data

Code

(define all-vehicles
  (sail-to "http://www.fueleconomy.gov/feg/epadata/vehicles.csv.zip"
           (load) (manifest)))

(define-struct auto (make model year trans city-mpg hwy-mpg))

(fetch-random all-vehicles (make-auto "make" "model" "year" "trany" "city08" "highway08"))
(data-length all-vehicles)     ; ~40,000 records!

Output

(make-auto "Saab" 900 1986 "Automatic 3-spd" 16 20)
39259

Makes (year-specific)

Code

(define makes-data
  (sail-to "http://www.fueleconomy.gov/ws/rest/vehicle/menu/make"
           (format "xml") (param "year" 2012) (load) (manifest)))

(define makes (fetch makes-data "menuItem/value"))

Output

> makes
(list
 "Acura"
 "Aston Martin"
 "Audi"
 ...)

Model options

Code

(define model-options
  (sail-to "http://www.fueleconomy.gov/ws/rest/vehicle/menu/options"
           (format "xml")
           (param "year" "2012") (param "make" "Honda") (param "model" "Fit")
           (load) (manifest)))

(fetch model-options (list "text" "value") (base-path "menuItem"))

Output

(list
 (list "Auto (S5), 4 cyl, 1.5 L" 31819)
 (list "Auto 5-spd, 4 cyl, 1.5 L" 31818)
 (list "Man 5-spd, 4 cyl, 1.5 L" 31817))

Specific Vehicle Data

See previous one for searching for vehicle IDs, or use https://www.fueleconomy.gov/feg/findacar.shtml to interactively search for a particular vehicle; then note the “id” query parameter in the URL that you are directed to.

Code

(fetch
 (sail-to "http://www.fueleconomy.gov/ws/rest/vehicle/31819"
         (format "xml") (load))
 (make-auto "make" "model" "year" "trany" "city08" "highway08"))  ; uses the struct definition above

Output

(make-auto "Honda" "Fit" 2012 "Automatic (S5)" 27 33)

Metadata (site-provided)