Assignment3

Question 1

We are examining the list of college majors from the FiveThiryEight article The Economic Guide To Picking A College Major.

Below we import the data from the FiveThirtyEight Github

library(tidyverse)

## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr     1.1.4     ✔ readr     2.1.5
## ✔ forcats   1.0.0     ✔ stringr   1.5.1
## ✔ ggplot2   3.4.4     ✔ tibble    3.2.1
## ✔ lubridate 1.9.3     ✔ tidyr     1.3.1
## ✔ purrr     1.0.2     
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors

library(readr)

fileURL = 'https://raw.githubusercontent.com/fivethirtyeight/data/master/college-majors/majors-list.csv'

majorsDF = read.csv((url(fileURL)))

We are interested in finding majors that contain the phrases “DATA” or “STATISTICS”

majorsOfInterest <- grep("DATA|STATISTICS", majorsDF$Major, value = TRUE, ignore.case = FALSE)

print(majorsOfInterest)

## [1] "MANAGEMENT INFORMATION SYSTEMS AND STATISTICS"
## [2] "COMPUTER PROGRAMMING AND DATA PROCESSING"     
## [3] "STATISTICS AND DECISION SCIENCE"

Question 2

We are interested in transforming the below vector into one line of output that is separated by commas

foodVector <- c("bell pepper", "bilberry", "blackberry", "blood orange", "blueberry", "cantaloupe", "chili pepper", "cloudberry", "elderberry", "lime", "lychee", "mulberry", "olive", "salal berry")

str_flatten_comma(foodVector)

## [1] "bell pepper, bilberry, blackberry, blood orange, blueberry, cantaloupe, chili pepper, cloudberry, elderberry, lime, lychee, mulberry, olive, salal berry"

Question 3

Describe, in words, what these expressions will match:

• (.)\1\1

  • find a string that has the same charter three times in a row

  • none of the strings in fruit or words fill the requirement

    str_view(fruit, "(.)\\1\\1")
    str_view(words, "(.)\\1\\1")
    
    str_view(c('abbba', 'goooal', 'ball'), "(.)\\1\\1") # returns only 'abbba' and 'goooal' with the repeating characters highlighted

    ## [1] │ a<bbb>a
    ## [2] │ g<ooo>al

• “(.)(.)\\2\\1”

  • find a string that has two characters followed by the same two characters but in reverse order

    str_view(words, "(.)(.)\\2\\1")

    ##  [19] │ after<noon>
    ##  [43] │ <appa>rent
    ##  [53] │ <arra>nge
    ## [107] │ b<otto>m
    ## [112] │ br<illi>ant
    ## [174] │ c<ommo>n
    ## [230] │ d<iffi>cult
    ## [259] │ <effe>ct
    ## [329] │ f<ollo>w
    ## [422] │ in<deed>
    ## [470] │ l<ette>r
    ## [521] │ m<illi>on
    ## [581] │ <oppo>rtunity
    ## [582] │ <oppo>se
    ## [877] │ tom<orro>w

• (..)\1

  • find a string that has the same two characters repeating

    str_view(words,"(..)\\1")

    ## [696] │ r<emem>ber

    str_view(fruit,"(..)\\1")

    ##  [4] │ b<anan>a
    ## [20] │ <coco>nut
    ## [22] │ <cucu>mber
    ## [41] │ <juju>be
    ## [56] │ <papa>ya
    ## [73] │ s<alal> berry

• “(.).\\1.\\1”

  • find a string that has a character, followed by a different character, followed by the original character, followed by a different character, followed by the original character

    str_view(words,"(.).\\1.\\1")

    ## [265] │ <eleve>n

    str_view(fruit,"(.).\\1.\\1")

    ##  [4] │ b<anana>
    ## [56] │ p<apaya>

• “(.)(.)(.).*\\3\\2\\1”

  • finds a string where there are three characters followed by any set of characters followed by the aforementioned three characters in reverse order

    str_view(words,"(.)(.)(.).*\\3\\2\\1")

    ## [598] │ <paragrap>h

Question 4

Construct regular expressions to match words that:

• Start and end with the same character.

  str_view(words, "^(.).*\\1$")

  ##  [36] │ <america>
  ##  [49] │ <area>
  ## [209] │ <dad>
  ## [213] │ <dead>
  ## [223] │ <depend>
  ## [258] │ <educate>
  ## [266] │ <else>
  ## [268] │ <encourage>
  ## [270] │ <engine>
  ## [278] │ <europe>
  ## [283] │ <evidence>
  ## [285] │ <example>
  ## [287] │ <excuse>
  ## [288] │ <exercise>
  ## [291] │ <expense>
  ## [292] │ <experience>
  ## [296] │ <eye>
  ## [386] │ <health>
  ## [394] │ <high>
  ## [450] │ <knock>
  ## ... and 16 more

• Contain a repeated pair of letters (e.g. “church” contains “ch” repeated twice.)

  str_view(words, "(..).*\\1")

  ##  [48] │ ap<propr>iate
  ## [152] │ <church>
  ## [181] │ c<ondition>
  ## [217] │ <decide>
  ## [275] │ <environmen>t
  ## [487] │ l<ondon>
  ## [598] │ pa<ragra>ph
  ## [603] │ p<articular>
  ## [617] │ <photograph>
  ## [638] │ p<repare>
  ## [641] │ p<ressure>
  ## [696] │ r<emem>ber
  ## [698] │ <repre>sent
  ## [699] │ <require>
  ## [739] │ <sense>
  ## [858] │ the<refore>
  ## [903] │ u<nderstand>
  ## [946] │ w<hethe>r

• Contain one letter repeated in at least three places (e.g. “eleven” contains three “e”s.)

  str_view(words, "(.).*\\1.*\\1")

  ##  [48] │ a<pprop>riate
  ##  [62] │ <availa>ble
  ##  [86] │ b<elieve>
  ##  [90] │ b<etwee>n
  ## [119] │ bu<siness>
  ## [221] │ d<egree>
  ## [229] │ diff<erence>
  ## [233] │ di<scuss>
  ## [265] │ <eleve>n
  ## [275] │ e<nvironmen>t
  ## [283] │ <evidence>
  ## [288] │ <exercise>
  ## [291] │ <expense>
  ## [292] │ <experience>
  ## [423] │ <indivi>dual
  ## [598] │ p<aragra>ph
  ## [684] │ r<eceive>
  ## [696] │ r<emembe>r
  ## [698] │ r<eprese>nt
  ## [845] │ t<elephone>
  ## ... and 2 more