Kaixin Wang
OSCR - Summer Session C 2019
Note: Some contents are based on the book An introduction to data cleaning with R, by Edwin de Jonge and Mark van der Loo.
library(readr)
input = read_csv("person_info.csv")
input# A tibble: 10 x 14
first_name last_name birthday age state address City phone email
<chr> <chr> <chr> <int> <chr> <chr> <chr> <chr> <chr>
1 Carol Davis 9/29/1996 23 Illin… 1674 Ca… Burr … 312-… curt…
2 Bruno Horan 6/11/1995 24 Calif… 1561 St… San D… 858-… guad…
3 William Moody 2/27/1997 22 Illin… 541 Jad… Arlin… 979-… roos…
4 Robin Steel 8/3/1989 57 Texas 1674 Ca… Josep… 214-… lloy…
5 Michelle Roberts 7/17/1995 24 Oregon 1372 Ga… "Port… 503-… ben1…
6 June Sneed 3/27/2000 19 Arizo… 2411 Cl… Phoen… 256-… kath…
7 Curtis Campbell 3/15/1991 28 Idahol 2760 Sc… Pocat… 979-… just…
8 Dorothy Schott 1/2/1997 21 Calif… 2742 Su… Santa… 501-… mega…
9 Mae Skinner 3/16/1995 24 Penns… <NA> Newar… 501-… enri…
10 David Victoria 8/2/1996 23 Maine 3327 Ch… Harps… 207-… caro…
# ... with 5 more variables: car_1 <chr>, gpa <dbl>, year <chr>,
# class_of <int>, online_signiture <chr>str() functionstr(input) # data structure of the objectClasses 'tbl_df', 'tbl' and 'data.frame': 10 obs. of 14 variables:
$ first_name : chr "Carol" "Bruno" "William" "Robin" ...
$ last_name : chr "Davis" "Horan" "Moody" "Steel" ...
$ birthday : chr "9/29/1996" "6/11/1995" "2/27/1997" "8/3/1989" ...
$ age : int 23 24 22 57 24 19 28 21 24 23
$ state : chr "Illinois" "California" "Illinois" "Texas" ...
$ address : chr "1674 Carolyns Circle" "1561 Still Street" "541 Jade wood Drive" "1674 Caroly ns Circle" ...
$ City : chr "Burr Ridge, Illinois(IL), 60527" "San Diego, California(CA), 92111" "Arlington Heights, Illinois(IL), 60004" "Josephine, Texas(TX), 75173" ...
$ phone : chr "312-295-1941" "858-449-3324" "979-614-4038" "214-694-7864" ...
$ email : chr "curt1995@gmail.com" "guadalupe1974@yahoo.com" "roosevelt.fee@hotmail.com" "lloyd2009@hotmail.com" ...
$ car_1 : chr "6ZUA618" "982KRK" "PS9-S917" "na" ...
$ gpa : num 2.85 3.47 2.78 4.33 3.75 3.6 2.32 3.93 3.85 1.74
$ year : chr "1" "2" "2" "4" ...
$ class_of : int 2022 2021 2021 2019 2019 2021 2020 2020 2020 2021
$ online_signiture: chr "Don't aim for success if you want it just do what you love and believe in" "In any investment, you expect to have fun and make money." "It's not my fault that people don't appreciate the art of unpunctuality." "The press is the hired agent of a monied system" ...
- attr(*, "spec")=List of 2
..$ cols :List of 14
.. ..$ first_name : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ last_name : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ birthday : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ age : list()
.. .. ..- attr(*, "class")= chr "collector_integer" "collector"
.. ..$ state : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ address : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ City : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ phone : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ email : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ car_1 : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ gpa : list()
.. .. ..- attr(*, "class")= chr "collector_double" "collector"
.. ..$ year : list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
.. ..$ class_of : list()
.. .. ..- attr(*, "class")= chr "collector_integer" "collector"
.. ..$ online_signiture: list()
.. .. ..- attr(*, "class")= chr "collector_character" "collector"
..$ default: list()
.. ..- attr(*, "class")= chr "collector_guess" "collector"
..- attr(*, "class")= chr "col_spec"summary() function:summary(input) # summary statistics of the object first_name last_name birthday age
Length:10 Length:10 Length:10 Min. :19.00
Class :character Class :character Class :character 1st Qu.:22.25
Mode :character Mode :character Mode :character Median :23.50
Mean :26.50
3rd Qu.:24.00
Max. :57.00
state address City
Length:10 Length:10 Length:10
Class :character Class :character Class :character
Mode :character Mode :character Mode :character
phone email car_1 gpa
Length:10 Length:10 Length:10 Min. :1.740
Class :character Class :character Class :character 1st Qu.:2.797
Mode :character Mode :character Mode :character Median :3.535
Mean :3.262
3rd Qu.:3.825
Max. :4.330
year class_of online_signiture
Length:10 Min. :2019 Length:10
Class :character 1st Qu.:2020 Class :character
Mode :character Median :2020 Mode :character
Mean :2020
3rd Qu.:2021
Max. :2022 class() and typeof() functionsclass(input$first_name) # class of the object[1] "character"typeof(input$first_name) # type of the object[1] "character"class(input$age) # class of the object[1] "integer"typeof(input$age) # type of the object[1] "integer"as.numeric, as.logical, as.integer, as.double, as.factor, and as.character
age <- input$age
summary(age) Min. 1st Qu. Median Mean 3rd Qu. Max.
19.00 22.25 23.50 26.50 24.00 57.00 as.double(age) [1] 23 24 22 57 24 19 28 21 24 23as.logical(age) # to a logical vector [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUEas.character(age) # to a character vector [1] "23" "24" "22" "57" "24" "19" "28" "21" "24" "23"as.factor(age) # to a factor [1] 23 24 22 57 24 19 28 21 24 23
Levels: 19 21 22 23 24 28 57as.logical:as.factor:lubridate librarylibrary(lubridate)Attaching package: 'lubridate'
The following object is masked from 'package:base':
datedates <- c("15/02/2013", "15 Feb 13", "It happened on 15 02 '13")
dmy(dates)[1] "2013-02-15" "2013-02-15" "2013-02-15"mdy(input$birthday) [1] "1996-09-29" "1995-06-11" "1997-02-27" "1989-08-03" "1995-07-17"
[6] "2000-03-27" "1991-03-15" "1997-01-02" "1995-03-16" "1996-08-02"Note: There are similar functions for all permutations of d, m and y. Explicitly, all of the following functions exist: dmy myd ydm mdy dym ymd.
library(stringr)
str_trim(" hello world ")[1] "hello world"str_trim(" hello world ", side = "left")[1] "hello world "str_trim(" hello world ", side = "right")[1] " hello world"toupper("Hello world")[1] "HELLO WORLD"tolower("Hello World")[1] "hello world"input$City[5][1] "Portland, Oregon(OR), 97217\n\n"input$City[5] = str_trim(input$City[5], side = "right")
input$City[5][1] "Portland, Oregon(OR), 97217"gender <- c("M", "male ", "Female", "fem.")
grepl("m", gender)[1] FALSE TRUE TRUE TRUEgrep("m", gender)[1] 2 3 4