DATA 607 - Assignment3 [R Character Manipulation]

Package Installs (optional)

library(“stringr”) library(“htmlwidgets”)

Libraries

library("stringr")
library("htmlwidgets")

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

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

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"

Problem 3.1

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

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str_view(name, '^([[:alpha:]]*\\. )?')

str_view(name, ',([ [:alpha:]]*\\.)?')

str_replace(name, '^([[:alpha:]]*\\. )?', '') %>% str_replace(pattern = ',([ [:alpha:]]*\\.)?', replacement =  '')

## [1] "Moe Szyslak"      "Burns Montgomery" "Timothy Lovejoy" 
## [4] "Ned Flanders"     "Simpson Homer"    "Julius Hibbert"

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Problem 3.2

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

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str_detect(name, '^([[:alpha:]]*\\. )')

## [1] FALSE FALSE  TRUE FALSE FALSE  TRUE

data.frame(names=name, has_title=str_detect(name, '^([[:alpha:]]*\\. )'))

##                  names has_title
## 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

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Problem 3.3

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

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str_detect(name, ',([ [:alpha:]]*\\.)?')

## [1] FALSE  TRUE FALSE FALSE  TRUE FALSE

data.frame(names=name, has_2nd_name=str_detect(name, ',([ [:alpha:]]*\\.)'))

##                  names has_2nd_name
## 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

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Problem 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]+\\$
   One or more digits ending with a “$” sign

str_view_all("2342$ abc$ 32$ abc4$", '[0-9]+\\$')

2. \\b[a-z]{1,4}\\b
   Lower case words up to 4 characters long

str_view_all("asdfs ABC a alsd dk asd sldkfss asdf asd 232 232asd abc2", "\\b[a-z]{1,4}\\b")

3. .*?\\.txt$
   Any string ending with “.txt” - R applies greedy quantification

str_view_all("as\\xyz912-s9d\abc.asdfsd.txt txt TXT abc.TXT .txt a.txt.abc abc.txt.xyz.txt", ".*?\\.txt$")

4. \\d{2}/\\d{2}/\\d{4}
   a string in the format of dd/dd/dddd - matching date in MM/DD/YYYY format for example

str_view_all("12/54/9493 234/1/4359 4/43/2232 02/15/2018", "\\d{2}/\\d{2}/\\d{4}")

5. <(.+?)>.+?</\\1>
   a string which is a content of an XML element

str_view_all("<abc>xyz</abc> <tag>abc</tag>", "<(.+?)>.+?</\\1>")

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