It can be very useful when trying to extract a value from somewhere, and you have one col that represents the unique id.
Arguments
- data
A data.frame
- var
A variable specified as:
a literal variable name
a positive integer, giving the position counting from the left
a negative integer, giving the position counting from the right.
The default returns the last column (on the assumption that's the column you've created most recently).
This argument is taken by expression and supports quasiquotation (you can unquote column names and column locations).
- filter
the filter
- name
The variable for the name (by default, will look for
rownames), can be quoted (safer).- length
A fixed length to check for the output
- unique
A logical. Should return unique values?
Examples
# extract the skin_color for C-3PO
extract_cell_value(
data = dplyr::starwars,
var = skin_color,
filter = name == "C-3PO",
length = 1 # ensure the length will be 1.
)
#> [1] "gold"
# will return a named vector of mpg (as mtcars has rownames.)
mtcars |>
extract_cell_value(
var = mpg,
filter = vs == 0
)
#> Mazda RX4 Mazda RX4 Wag Hornet Sportabout Duster 360
#> 21.0 21.0 18.7 14.3
#> Merc 450SE Merc 450SL Merc 450SLC Cadillac Fleetwood
#> 16.4 17.3 15.2 10.4
#> Lincoln Continental Chrysler Imperial Dodge Challenger AMC Javelin
#> 10.4 14.7 15.5 15.2
#> Camaro Z28 Pontiac Firebird Porsche 914-2 Ford Pantera L
#> 13.3 19.2 26.0 15.8
#> Ferrari Dino Maserati Bora
#> 19.7 15.0
# Extract hair color for all people
extract_cell_value(
data = dplyr::starwars,
var = skin_color,
filter = TRUE,
name = "name" # ensure it is a named vector that corresponds to their unique ID
)
#> Luke Skywalker C-3PO R2-D2
#> "fair" "gold" "white, blue"
#> Darth Vader Leia Organa Owen Lars
#> "white" "light" "light"
#> Beru Whitesun Lars R5-D4 Biggs Darklighter
#> "light" "white, red" "light"
#> Obi-Wan Kenobi Anakin Skywalker Wilhuff Tarkin
#> "fair" "fair" "fair"
#> Chewbacca Han Solo Greedo
#> "unknown" "fair" "green"
#> Jabba Desilijic Tiure Wedge Antilles Jek Tono Porkins
#> "green-tan, brown" "fair" "fair"
#> Yoda Palpatine Boba Fett
#> "green" "pale" "fair"
#> IG-88 Bossk Lando Calrissian
#> "metal" "green" "dark"
#> Lobot Ackbar Mon Mothma
#> "light" "brown mottle" "fair"
#> Arvel Crynyd Wicket Systri Warrick Nien Nunb
#> "fair" "brown" "grey"
#> Qui-Gon Jinn Nute Gunray Finis Valorum
#> "fair" "mottled green" "fair"
#> Padmé Amidala Jar Jar Binks Roos Tarpals
#> "light" "orange" "grey"
#> Rugor Nass Ric Olié Watto
#> "green" "fair" "blue, grey"
#> Sebulba Quarsh Panaka Shmi Skywalker
#> "grey, red" "dark" "fair"
#> Darth Maul Bib Fortuna Ayla Secura
#> "red" "pale" "blue"
#> Ratts Tyerel Dud Bolt Gasgano
#> "grey, blue" "blue, grey" "white, blue"
#> Ben Quadinaros Mace Windu Ki-Adi-Mundi
#> "grey, green, yellow" "dark" "pale"
#> Kit Fisto Eeth Koth Adi Gallia
#> "green" "brown" "dark"
#> Saesee Tiin Yarael Poof Plo Koon
#> "pale" "white" "orange"
#> Mas Amedda Gregar Typho Cordé
#> "blue" "dark" "light"
#> Cliegg Lars Poggle the Lesser Luminara Unduli
#> "fair" "green" "yellow"
#> Barriss Offee Dormé Dooku
#> "yellow" "light" "fair"
#> Bail Prestor Organa Jango Fett Zam Wesell
#> "tan" "tan" "fair, green, yellow"
#> Dexter Jettster Lama Su Taun We
#> "brown" "grey" "grey"
#> Jocasta Nu R4-P17 Wat Tambor
#> "fair" "silver, red" "green, grey"
#> San Hill Shaak Ti Grievous
#> "grey" "red, blue, white" "brown, white"
#> Tarfful Raymus Antilles Sly Moore
#> "brown" "light" "pale"
#> Tion Medon Finn Rey
#> "grey" "dark" "light"
#> Poe Dameron BB8 Captain Phasma
#> "light" "none" "none"