checkUnitPrefix: Check For Common Unit-Name in Text

Description

This function aims to find a unit abbreviation or name occurring in all elements of a character-vector x. The unit name may be preceeded by different decimal prefixes (eg 'k','M'), as defined by argument pref and separators (sep). The unit name will be returned (or first of multiple).

Usage

checkUnitPrefix(
  x,
  pref = c("a", "f", "p", "n", "u", "m", "", "k", "M", "G", "T", "P"),
  unit = c("m", "s", "sec", "Mol", "mol", "g", "K", "cd", "A", "W", "Watt", "V", "Volt"),
  sep = c("", " ", ";", ",", "_", "."),
  sep2 = "",
  stringentSearch = FALSE,
  na.rm = FALSE,
  protSpecChar = TRUE,
  inclPat = FALSE,
  callFrom = NULL,
  silent = FALSE,
  debug = FALSE
)

Value

This function returns a charcter vector (length=1) with the common unit name, if inclPat=TRUE it returns a list with $unit and $pattern

Arguments

x: (character) vector containing digit uunit-prefix and unit terms
pref: (character) multiplicative unit-prefixes, assumes as increasing factors of 1000
unit: (character) unit name, the numeric part may be sepatated by one space-character
sep: (character) separator character(s) that may appear between integer numeric value and unit-prefix
sep2: (character) separator character(s) after unit, set to sep2="" for ignoring characters following unit
stringentSearch: (logical) if TRUE only matches with same separators (sep, sep2) pass, otherwise different elements may contain different separators
na.rm: (logical) remove NA from input
protSpecChar: (logical) protect special characters and use as they are instead of regex-meaning
inclPat: (logical) return list including pattern of successful search
callFrom: (character) allow easier tracking of messages produced
silent: (logical) suppress messages
debug: (logical) additional messages for debugging

Details

Basically this function searches the pattern : digit + separator(sep) + prefix(pref) + unit + optional separator2(sep2) and returns the first unit-name/abbreviation found in all elements of x.

If if() In case of invalid entries or no common unit-names NULL will be returned.

Please note the 'u' is used for 'micro' since handeling of special characters may not be portal between different operating systems.

Examples

Run this code

x1 <- c("10fg WW","xx 10fg 3pW"," 1pg 2.0W")
checkUnitPrefix(x1)
## different separators between digit and prefix:
x2 <- c("10fg WW","xx 8_fg 3pW"," 1 pg-2.0W")
checkUnitPrefix(x2, stringentSearch=TRUE)
checkUnitPrefix(x2, stringentSearch=FALSE)

x4 <- c("CT_mixture_QY_50_amol_CN_UPS1_CV_Standards_Research_Group",
  "CT_mixture_QY_5_fmol_CN_UPS1_CV_Standards_Research_Group")