case-insensitive value-grep for a vector of patterns
case-insensitive grep for a vector of patterns
Usage
provigrep(
patterns,
x,
maxValues = NULL,
sortFunc = c,
rev = FALSE,
returnType = c("vector", "list"),
ignore.case = TRUE,
value = TRUE,
...
)
proigrep(..., value = FALSE)Arguments
- patterns
charactervector of regular expression patterns, ultimately passed tobase::grep().- x
charactervector that is the subject ofbase::grep().- maxValues
integeror NULL, the maximum matching entries to return per grep pattern. Note that each grep pattern may match multiple values, and values are only returned at most once each, so restricting items returned by one grep pattern may allow an item to be matched by subsequent patterns, see examples. This argument is most commonly used withmaxValues=1which returns only the first matching entry per pattern.- sortFunc
functionor NULL, used to sort entries within each set of matching entries. Use NULL to avoid sorting entries.- rev
logicalwhether to reverse the order of matching entries. Use TRUE if you would like entries matching the patterns to be placed last, and entries not matching the grep patterns to be placed first. This technique is effective at placing "noise names" at the end of a long vector, for example.- returnType
characterindicating whether to return a vector or list. A list will be in order of the grep patterns, using empty elements to indicate when no entries matched each pattern. This output is useful when you would like to know which patterns matched specific entries.- ignore.case
logicalparameter sent tobase::grep(), TRUE runs in case-insensitive mode, as by default.- value
logicalindicating whether to return the matched value, or whenvalue=FALSEthe index position is returned.- ...
additional arguments are passed to
vigrep().
Value
character vector with entries in x reordered to match
the order of patterns provided, or list when returnType="list"
named by patterns in the order provided. When value=FALSE then
it returns integer index values of x.
Details
Purpose is to provide "progressive vigrep()",which is value-returning, case-insensitive grep, starting with an ordered vector of grep patterns. For example, it returns entries in the order they are matched, by the progressive use of grep patterns.
It is particularly good when using multiple grep patterns, since
grep() does not accept multiple patterns as input. This function
also only returns the unique matches in the order they were matched,
which alleviates the need to run a series of grep() functions
and collating their results.
It is mainly to allow for prioritized ordering of matching entries, where one would like certain matching entries first, followed by another set of matching entries, without duplication. For example, one might grep for a few patterns, but want certain pattern hits to be listed first.
Examples
# a rather comical example
# set up a test set with labels containing several substrings
set.seed(1);
testTerms <- c("robot","tree","dog","mailbox","pizza","noob");
testWords <- pasteByRow(t(combn(testTerms,3)));
# now pull out entries matching substrings in order
provigrep(c("pizza", "dog", "noob", "."), testWords);
#> 3 6 8
#> "robot_tree_pizza" "robot_dog_pizza" "robot_mailbox_pizza"
#> 10 12 14
#> "robot_pizza_noob" "tree_dog_pizza" "tree_mailbox_pizza"
#> 16 17 19
#> "tree_pizza_noob" "dog_mailbox_pizza" "dog_pizza_noob"
#> 20 1 5
#> "mailbox_pizza_noob" "robot_tree_dog" "robot_dog_mailbox"
#> 7 11 13
#> "robot_dog_noob" "tree_dog_mailbox" "tree_dog_noob"
#> 18 4 9
#> "dog_mailbox_noob" "robot_tree_noob" "robot_mailbox_noob"
#> 15 2
#> "tree_mailbox_noob" "robot_tree_mailbox"
# more detail about the sort order is shown with returnType="list"
provigrep(c("pizza", "dog", "noob", "."), testWords, returnType="list");
#> $pizza
#> 3 6 8
#> "robot_tree_pizza" "robot_dog_pizza" "robot_mailbox_pizza"
#> 10 12 14
#> "robot_pizza_noob" "tree_dog_pizza" "tree_mailbox_pizza"
#> 16 17 19
#> "tree_pizza_noob" "dog_mailbox_pizza" "dog_pizza_noob"
#> 20
#> "mailbox_pizza_noob"
#>
#> $dog
#> 1 5 7 11
#> "robot_tree_dog" "robot_dog_mailbox" "robot_dog_noob" "tree_dog_mailbox"
#> 13 18
#> "tree_dog_noob" "dog_mailbox_noob"
#>
#> $noob
#> 4 9 15
#> "robot_tree_noob" "robot_mailbox_noob" "tree_mailbox_noob"
#>
#> $.
#> 2
#> "robot_tree_mailbox"
#>
# rev=TRUE will reverse the order of the list
provigrep(c("pizza", "dog", "noob", "."), testWords, returnType="list", rev=TRUE);
#> $.
#> 2
#> "robot_tree_mailbox"
#>
#> $noob
#> 4 9 15
#> "robot_tree_noob" "robot_mailbox_noob" "tree_mailbox_noob"
#>
#> $dog
#> 1 5 7 11
#> "robot_tree_dog" "robot_dog_mailbox" "robot_dog_noob" "tree_dog_mailbox"
#> 13 18
#> "tree_dog_noob" "dog_mailbox_noob"
#>
#> $pizza
#> 3 6 8
#> "robot_tree_pizza" "robot_dog_pizza" "robot_mailbox_pizza"
#> 10 12 14
#> "robot_pizza_noob" "tree_dog_pizza" "tree_mailbox_pizza"
#> 16 17 19
#> "tree_pizza_noob" "dog_mailbox_pizza" "dog_pizza_noob"
#> 20
#> "mailbox_pizza_noob"
#>
provigrep(c("pizza", "dog", "noob", "."), testWords, rev=TRUE);
#> 2 4 9
#> "robot_tree_mailbox" "robot_tree_noob" "robot_mailbox_noob"
#> 15 1 5
#> "tree_mailbox_noob" "robot_tree_dog" "robot_dog_mailbox"
#> 7 11 13
#> "robot_dog_noob" "tree_dog_mailbox" "tree_dog_noob"
#> 18 3 6
#> "dog_mailbox_noob" "robot_tree_pizza" "robot_dog_pizza"
#> 8 10 12
#> "robot_mailbox_pizza" "robot_pizza_noob" "tree_dog_pizza"
#> 14 16 17
#> "tree_mailbox_pizza" "tree_pizza_noob" "dog_mailbox_pizza"
#> 19 20
#> "dog_pizza_noob" "mailbox_pizza_noob"
# another example showing ordering of duplicated entries
set.seed(1);
x <- paste0(
sample(letters[c(1,2,2,3,3,3,4,4,4,4)]),
sample(1:5));
x;
#> [1] "d3" "c5" "d1" "a4" "b2" "c3" "b5" "d1" "c4" "d2"
# sort by letter
provigrep(letters[1:4], x)
#> [1] "a4" "b2" "b5" "c5" "c3" "c4" "d3" "d1" "d1" "d2"
# show more detail about how the sort is performed
provigrep(letters[1:4], x, returnType="list")
#> $a
#> [1] "a4"
#>
#> $b
#> [1] "b2" "b5"
#>
#> $c
#> [1] "c5" "c3" "c4"
#>
#> $d
#> [1] "d3" "d1" "d1" "d2"
#>
# rev=TRUE will reverse the order of pattern matching
# which is most useful when "." is the last pattern:
provigrep(c(letters[1:3], "."), x, returnType="list")
#> $a
#> [1] "a4"
#>
#> $b
#> [1] "b2" "b5"
#>
#> $c
#> [1] "c5" "c3" "c4"
#>
#> $.
#> [1] "d3" "d1" "d1" "d2"
#>
provigrep(c(letters[1:3], "."), x, returnType="list", rev=TRUE)
#> $.
#> [1] "d3" "d1" "d1" "d2"
#>
#> $c
#> [1] "c5" "c3" "c4"
#>
#> $b
#> [1] "b2" "b5"
#>
#> $a
#> [1] "a4"
#>
# example demonstrating maxValues
# return in list format
provigrep(c("[ABCD]", "[CDEF]", "[FGHI]"), LETTERS, returnType="list")
#> $`[ABCD]`
#> [1] "A" "B" "C" "D"
#>
#> $`[CDEF]`
#> [1] "E" "F"
#>
#> $`[FGHI]`
#> [1] "G" "H" "I"
#>
# maxValues=1
provigrep(c("[ABCD]", "[CDEF]", "[FGHI]"), LETTERS, returnType="list", maxValues=1)
#> $`[ABCD]`
#> [1] "A"
#>
#> $`[CDEF]`
#> [1] "C"
#>
#> $`[FGHI]`
#> [1] "F"
#>
provigrep(c("[ABCD]", "[CDEF]", "[FGHI]"), LETTERS, returnType="list", maxValues=1, value=FALSE)
#> $`[ABCD]`
#> [1] 1
#>
#> $`[CDEF]`
#> [1] 3
#>
#> $`[FGHI]`
#> [1] 6
#>
proigrep(c("[ABCD]", "[CDEF]", "[FGHI]"), LETTERS, maxValues=1)
#> [1] 1 3 6