DATA607 - Homerwork 3 Ch. 8

3. Copy the introductory example. The vector name stores the extracted names. R> name [1] “Moe Szyslak” “Burns, C. Montgomery” “Rev. Timothy Lovejoy” [4] “Ned Flanders” “Simpson, Homer” “Dr. Julius Hibbert”

1. Use the tools of this chapter to rearrange the vector so that all elements conform to the standard first_name last_name.

2. Construct a logical vector indicating whether a character has a title (i.e., Rev. and Dr.).

3. Construct a logical vector indicating whether a character has a second name.

raw.data <-"555-1239Moe Szyslak(636) 555-0113Burns, C. Montgomery555-6542Rev. Timothy Lovejoy555 8904Ned Flanders636-555-3226Simpson, Homer5553642Dr. Julius Hibbert"

3. Copy the introductory example. The vector name stores the extracted names. R> name [1] “Moe Szyslak” “Burns, C. Montgomery” “Rev. Timothy Lovejoy” [4] “Ned Flanders” “Simpson, Homer” “Dr. Julius Hibbert”

Extrating names, we use the following regex ‘[[:alpha:]., ]{2,}’ [:alpha:] is to indicate all letters in the alphabet, we add ., and ’ ’ in the our regex, as names can contain a period, comma, or a space along with the letters. Finally we indicated a quantifier {min, max}, but only indicated a min value of 2, and max of none. This way our extraction will only occur if there is a minimun of two vaules found with our regex. This prevents the extraction of all single characters.

name <- unlist(str_extract_all(raw.data, "[[:alpha:]., ]{2,}"))
name

## [1] "Moe Szyslak"          "Burns, C. Montgomery" "Rev. Timothy Lovejoy"
## [4] "Ned Flanders"         "Simpson, Homer"       "Dr. Julius Hibbert"

3(a) Use the tools of this chapter to rearrange the vector so that all elements conform to the standard first_name last_name.

1. Seperate out the first names regex desc (used str_extract to get just the first occurrence) a. all letters at least 3 letters before a space b. space then at least 3 letters c. do a str_extract on the extractaction in a and b to get only letters
2. Seperate out the last names a. at least 1 letter followed by a comma b. end of word followed by a space than atleast 3 letters c. extract a and b to get only letters
3. Combine first and last name a. concatinate firstName and lastName with space in between to get a dataframe with ‘firstname lastname’ format

firstName <- str_extract(str_extract(name, "[[:alpha:]]{3,} | [[:alpha:]]{3,}"), "[[:alpha:]]{1,}")
firstName

## [1] "Moe"        "Montgomery" "Timothy"    "Ned"        "Homer"     
## [6] "Julius"

lastName <- str_extract(str_extract(name, "[[:alpha:]]{1,}\\,|\\b [[:alpha:]]{3,}"), "[[:alpha:]]{1,}")
lastName

## [1] "Szyslak"  "Burns"    "Lovejoy"  "Flanders" "Simpson"  "Hibbert"

fullName <- data.frame(name = paste(firstName," ",lastName))
fullName

##                 name
## 1      Moe   Szyslak
## 2 Montgomery   Burns
## 3  Timothy   Lovejoy
## 4     Ned   Flanders
## 5    Homer   Simpson
## 6   Julius   Hibbert

3(b) Construct a logical vector indicating whether a character has a title (i.e., Rev. and Dr.). Use str_detect to determine the following regex: at least 2 letters with a period at the end.

title <- data.frame(fullName = name, hasTitle = str_detect(name, "[:alpha:]{2,}\\."))
title

##               fullName hasTitle
## 1          Moe Szyslak    FALSE
## 2 Burns, C. Montgomery    FALSE
## 3 Rev. Timothy Lovejoy     TRUE
## 4         Ned Flanders    FALSE
## 5       Simpson, Homer    FALSE
## 6   Dr. Julius Hibbert     TRUE

3(c) Construct a logical vector indicating whether a character has a second name. use str_detect to determing the following regex: exactly 1 letter after a space and ending with a period

secondName <- data.frame(fullName = name, hasSecondName = str_detect(name, " [:alpha:]{1}\\."))
secondName

##               fullName hasSecondName
## 1          Moe Szyslak         FALSE
## 2 Burns, C. Montgomery          TRUE
## 3 Rev. Timothy Lovejoy         FALSE
## 4         Ned Flanders         FALSE
## 5       Simpson, Homer         FALSE
## 6   Dr. Julius Hibbert         FALSE

4. Describe the types of strings that conform to the following regular expressions and construct an example that is matched by the regular expression.

1. [0-9]+\$ - any amount of numbers then a dollar sign. ex.“123\(dajfk." match = "123\)”

myExample <- "123$dajfk."
result <- str_extract(myExample, "[0-9]+\\$")
result

## [1] "123$"

2. \b[a-z]{1,4}\b - pattern that begins at the end of a word, all lowercase, exactly a lenght of 4 with and ending. ex. “WHAT that is?” match = “that”

myExample2 <- "WHAT that is?"
result2 <- str_extract(myExample2, "\\b[a-z]{1,4}\\b")
result2

## [1] "that"

3. .*?\.txt$ - string that ends in .txt

myExample3 <- "blability blam23jkd akfda.jpg fjdskf.txt"
result3 <-  str_extract(myExample3, ".*?\\.txt$")
result3

## [1] "blability blam23jkd akfda.jpg fjdskf.txt"

4. \d{2}/\d{2}/\d{4} - will extract any digits formatted like so: dd/dd/dddd

myExample4 <- "2131fjdksa 323 09/15/2019riew83"
result4 <- str_extract(myExample4, "\\d{2}/\\d{2}/\\d{4}")
result4

## [1] "09/15/2019"

5. <(.+?)>.+?</\1> - any string starting with and ending with

myExample5 <- "<p> blah blah paragraph </p> daslj212 !jlsakjf"
result5 <- str_extract(myExample5, "<(.+?)>.+?</\\1>")
result5

## [1] "<p> blah blah paragraph </p>"

9. The following code hides a secret message. Crack it with R and regular expressions. Hint: Some of the characters are more revealing than others! The code snippet is also available in the materials at www.r-datacollection.com. clcopCow1zmstc0d87wnkig7OvdicpNuggvhryn92Gjuwczi8hqrfpRxs5Aj5dwpn0Tanwo Uwisdij7Lj8kpf03AT5Idr3coc0bt7yczjatOaootj55t3Nj3ne6c4Sfek.r1w1YwwojigO d6vrfUrbz2.2bkAnbhzgv4R9i05zEcrop.wAgnb.SqoU65fPa1otfb7wEm24k6t3sR9zqe5 fy89n6Nd5t9kc4fE905gmc4Rgxo5nhDk!gr

encoded <- "clcopCow1zmstc0d87wnkig7OvdicpNuggvhryn92Gjuwczi8hqrfpRxs5Aj5dwpn0Tanwo
Uwisdij7Lj8kpf03AT5Idr3coc0bt7yczjatOaootj55t3Nj3ne6c4Sfek.r1w1YwwojigO
d6vrfUrbz2.2bkAnbhzgv4R9i05zEcrop.wAgnb.SqoU65fPa1otfb7wEm24k6t3sR9zqe5
fy89n6Nd5t9kc4fE905gmc4Rgxo5nhDk!gr"

decoded <- str_replace_all(paste0(unlist(str_extract_all(encoded, "[[A-Z][:punct:]]")), collapse = ""), "\\.", "\\ ")
decoded 

## [1] "CONGRATULATIONS YOU ARE A SUPERNERD!"