regexpr: Pattern Matching

In Fuzzy-Logix/AdapteR: Converts R syntax to SQL to provide fast analytics using in-database C++ library DB Lytix.

Description

Match pattern in each element of text

Usage

regexpr(pattern, text, ignore.case = FALSE, perl = FALSE, fixed = FALSE,
  useBytes = FALSE, startpos = 1)

Arguments

pattern	string to search for
text	FLVector of characters or R vector to be searched. where matches are sought
ignore.case	logical indicating case-sensitivity. Currently always FALSE for FLVectors
perl	logical. Should perl-compatible regexps be used? Always FALSE for FLVectors
fixed	logical. If TRUE, pattern is a string to be matched as is. For FLVectors, regualar expressions are not supported
useBytes	If TRUE the matching is done byte-by-byte rather than character-by-character. Always FALSE for FLVector
startpos	integer(numeric) specifying starting position for each search

Details

The DB Lytix function called is FLInstr.This function returns the position of the first occurrence of one string within another starting from the search position indicated.

Value

FLVector with position of first match or -1 for no match or R Vector

Constraints

row FLVectors are not supported currently.

See Also

regexpr for R function reference implementation.

Examples

widetable  <- FLTable("tblstringID", "stringID")
flv <- widetable[1:6,"string"]
resultflvector <- regexpr("A",flv)

Fuzzy-Logix/AdapteR documentation built on May 6, 2019, 5:07 p.m.