Select (or deselect) rows or columns — select_rows_cols

Arguments indicate which columns are to be retained and which are to be removed by routing to select_rows_byname() or select_cols_byname() based on the value of margin. margin can be a string or vector of strings that are matched to row and column types.

Usage

select_rows_cols_byname(
  a,
  margin = c(1, 2),
  retain_pattern = "$^",
  remove_pattern = "$^",
  ignore.case = FALSE,
  perl = FALSE,
  fixed = FALSE,
  useBytes = FALSE
)

Arguments

a: A matrix or a list of matrices.
margin: 1 for rows, 2 for columns, or c(1, 2) (the default) for both. Can be a string or vector of strings that indicate row and/or column types.
retain_pattern: An extended regex or list of extended regular expressions that specifies which columns of m to retain. Default pattern ("$^") retains nothing.
remove_pattern: An extended regex or list of extended regular expressions that specifies which columns of m to remove. Default pattern ("$^") removes nothing.
ignore.case, perl, fixed, useBytes: Arguments passed to grep().

Value

A matrix that is a subset of a with columns selected by retain_pattern and remove_pattern.

Details

If a is NULL, NULL is returned.

For maximum flexibility, arguments can be extended regex patterns that are matched against row or column names. If no row or column (depending on margin) names of a match the retain_pattern, NULL is returned. If no row or column (depending on margin) names of a match the remove_pattern, a is returned.

Retaining takes precedence over removing, always.

Some typical patterns are:

"^Electricity$|^Oil$": row or column names that are EXACTLY "Electricity" or "Oil".
"^Electricity|^Oil": row or column names that START WITH "Electricity" or "Oil".
"Electricity|Oil": row or column names that CONTAIN "Electricity" or "Oil" anywhere within them.

If the row or column labels contain "[" or "]", care should be taken to escape those characters. Hmisc::escapeRegex() is helpful in such situations. This function assumes that retain_pattern and remove_pattern have already been suitably escaped.

Given a list of row or column names, a pattern can be constructed easily using RCLabels::make_or_pattern(). RCLabels::make_or_pattern() escapes regex strings using Hmisc::escapeRegex().

Note that the default retain_pattern and remove_pattern ("$^") retain nothing and remove nothing.

Note that if all columns are removed from a, NULL is returned.

Examples

m <- matrix(1:16, ncol = 4, dimnames=list(c(paste0("i", 1:4)), paste0("p", 1:4))) |> 
  setrowtype("Industries") |> setcoltype("Commodities")
select_rows_cols_byname(m, 
                        margin = 2, # for columns
                        retain_pattern = RCLabels::make_or_pattern(c("p1", "p4"), 
                        pattern_type = "exact"))
#>    p1 p4
#> i1  1 13
#> i2  2 14
#> i3  3 15
#> i4  4 16
#> attr(,"rowtype")
#> [1] "Industries"
#> attr(,"coltype")
#> [1] "Commodities"
select_rows_cols_byname(m, 
                        margin = 2, 
                        remove_pattern = RCLabels::make_or_pattern(c("p1", "p3"), 
                        pattern_type = "exact"))
#>    p2 p4
#> i1  5 13
#> i2  6 14
#> i3  7 15
#> i4  8 16
#> attr(,"rowtype")
#> [1] "Industries"
#> attr(,"coltype")
#> [1] "Commodities"
# Also works for lists and data frames
select_rows_cols_byname(list(m,m), margin = 2, 
                        retain_pattern = "^p1$|^p4$")
#> [[1]]
#>    p1 p4
#> i1  1 13
#> i2  2 14
#> i3  3 15
#> i4  4 16
#> attr(,"rowtype")
#> [1] "Industries"
#> attr(,"coltype")
#> [1] "Commodities"
#> 
#> [[2]]
#>    p1 p4
#> i1  1 13
#> i2  2 14
#> i3  3 15
#> i4  4 16
#> attr(,"rowtype")
#> [1] "Industries"
#> attr(,"coltype")
#> [1] "Commodities"
#>