DATA 607 - Assignment #3

Question #1

Using the 173 majors listed in fivethirtyeight.com’s College Majors dataset [https://fivethirtyeight.com/features/the-economic-guide-to-picking-a-college-major/], provide code that identifies the majors that contain either “DATA” or “STATISTICS”

college_majors = read_csv('https://raw.githubusercontent.com/fivethirtyeight/data/master/college-majors/majors-list.csv', 
                          show_col_types = FALSE)

college_majors %>% filter(str_detect(Major,"STATISTICS") | str_detect(Major,"DATA"))

## # A tibble: 3 × 3
##   FOD1P Major                                         Major_Category         
##   <chr> <chr>                                         <chr>                  
## 1 6212  MANAGEMENT INFORMATION SYSTEMS AND STATISTICS Business               
## 2 2101  COMPUTER PROGRAMMING AND DATA PROCESSING      Computers & Mathematics
## 3 3702  STATISTICS AND DECISION SCIENCE               Computers & Mathematics

Question #2

Write code that transforms the data below:

[1] “bell pepper” “bilberry” “blackberry” “blood orange” [5] “blueberry” “cantaloupe” “chili pepper” “cloudberry”
[9] “elderberry” “lime” “lychee” “mulberry”
[13] “olive” “salal berry”

Into a format like this:

c(“bell pepper”, “bilberry”, “blackberry”, “blood orange”, “blueberry”, “cantaloupe”, “chili pepper”, “cloudberry”, “elderberry”, “lime”, “lychee”, “mulberry”, “olive”, “salal berry”)

## [1] "[1] \"bell pepper\"  \"bilberry\"     \"blackberry\"   \"blood orange\"\n[5] \"blueberry\"    \"cantaloupe\"   \"chili pepper\" \"cloudberry\" \n[9] \"elderberry\"   \"lime\"         \"lychee\"       \"mulberry\" \n[13] \"olive\"        \"salal berry\""

## [1] "c(\"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

This matches 3 consecutive matches of a character e.g. in string “422-3777”, it would match 777

• (.)(.)\2\1

This matches a character followed by a second character repeated twice followed by the first character again. e.g. in string “gamma”, it would match amma

• (..)\1

This matches 2 characters repeated twice e.g. in string “cucumber”, it would match cucu

• “(.).\1.\1”

This matches a character followed by any other character, followed by the first character, followed by any other character, followed by the first character e.g. in string “707372456”, it would match 70737

• “(.)(.)(.).*\3\2\1”

This matches any 3 characters, followed by 0 or more additional characters, followed by the 3rd character, then the 2nd character, and lastly the 1st character. e.g. in string “4563abc45643cba1231, it would match abc45643cba

Question #4

Construct regular expressions to match words that:

• Start and end with the same character:

**^(.).*\1$**

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

**(..).*\1**

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

(.).\1.\1