sortX extends the base sort() function by providing
a consistent interface for sorting not only vectors, but also matrices,
tables, and data frames. For 2-dimensional objects, rows are sorted based
on one or more columns.
Usage
sortX(x, ...)
# Default S3 method
sortX(
x,
decreasing = FALSE,
na.last = NA,
method = c("default", "mixed"),
factorsAsCharacter = TRUE,
...
)
# S3 method for class 'table'
sortX(
x,
ord = NULL,
decreasing = FALSE,
na.last = TRUE,
method = c("default", "mixed"),
factorsAsCharacter = TRUE,
...
)
# S3 method for class 'matrix'
sortX(
x,
ord = NULL,
decreasing = FALSE,
na.last = TRUE,
method = c("default", "mixed"),
factorsAsCharacter = TRUE,
...
)
# S3 method for class 'data.frame'
sortX(
x,
ord = NULL,
decreasing = FALSE,
na.last = TRUE,
method = c("default", "mixed"),
factorsAsCharacter = TRUE,
...
)Arguments
- x
a numeric, complex, character or logical vector, factor, matrix, table, or data frame to be sorted.
- ...
further arguments passed to
sort()insortX.default.- decreasing
logical scalar or vector. Should the sort be in decreasing order? For 2-dimensional objects a vector of the same length as
ordmay be supplied to control the direction per column; a scalar is recycled.- na.last
logical or
NA. Should missing values be placed last (TRUE), first (FALSE), or removed (NA)? Seeorder().- method
sorting method. Either
"default"(base R behavior) or"mixed"for natural sorting of character data (e.g."A2"<"A10").- factorsAsCharacter
logical. If
TRUE(default), factors are converted to character before sorting so that labels are used instead of level codes. Set toFALSEto sort by level order (useful for ordered factors).- ord
integer or character vector specifying the columns to sort by, and their priority (first element = primary key). Column names and positive integer indices (
1:ncol(x)) refer to columns. The special value0L(integer zero, always numeric) sorts by row names. Fortableandmatrixobjects,ncol(x) + 1Lsorts by row marginal sums. This argument is not available forsortX.default. Default:NULL(all columns, left to right).
Details
By default, sorting follows the behavior of base R. In addition,
method = "mixed" enables natural ("human-friendly") sorting of
character data, e.g. "A2" < "A10".
For method = "mixed", sorting is applied column-wise using
.orderMixed(). Each column's tokens are ordered independently
(numeric runs numerically, text runs lexicographically) before the
results are combined via stable right-to-left ordering.
The sort order for factors depends on factorsAsCharacter:
if TRUE (default), factors are sorted by their labels
(alphabetically or by natural order when method = "mixed");
if FALSE, they are sorted by their level order, which is
appropriate for ordered factors but may be unintuitive for unordered ones.
See also
Other data.order:
binaryTree(),
revX()
Examples
set.seed(3)
d.frm <- iris[sample(nrow(iris), 10),
c("Species", "Sepal.Length", "Sepal.Width")]
# Vector sorting
sortX(d.frm[, 1])
#> [1] setosa setosa setosa setosa versicolor virginica
#> [7] virginica virginica virginica virginica
#> Levels: setosa versicolor virginica
# Data frame: sort by column name
sortX(d.frm, ord = "Species")
#> Species Sepal.Length Sepal.Width
#> 5 setosa 5.0 3.6
#> 36 setosa 5.0 3.2
#> 20 setosa 5.1 3.8
#> 48 setosa 4.6 3.2
#> 74 versicolor 6.1 2.8
#> 140 virginica 6.9 3.1
#> 107 virginica 4.9 2.5
#> 136 virginica 7.7 3.0
#> 104 virginica 6.3 2.9
#> 146 virginica 6.7 3.0
sortX(d.frm, ord = c("Species", "Sepal.Length"))
#> Species Sepal.Length Sepal.Width
#> 48 setosa 4.6 3.2
#> 5 setosa 5.0 3.6
#> 36 setosa 5.0 3.2
#> 20 setosa 5.1 3.8
#> 74 versicolor 6.1 2.8
#> 107 virginica 4.9 2.5
#> 104 virginica 6.3 2.9
#> 146 virginica 6.7 3.0
#> 140 virginica 6.9 3.1
#> 136 virginica 7.7 3.0
# Data frame: sort by column index
sortX(d.frm, ord = c(1L, 2L))
#> Species Sepal.Length Sepal.Width
#> 48 setosa 4.6 3.2
#> 5 setosa 5.0 3.6
#> 36 setosa 5.0 3.2
#> 20 setosa 5.1 3.8
#> 74 versicolor 6.1 2.8
#> 107 virginica 4.9 2.5
#> 104 virginica 6.3 2.9
#> 146 virginica 6.7 3.0
#> 140 virginica 6.9 3.1
#> 136 virginica 7.7 3.0
# Decreasing order (per-column control)
sortX(d.frm, ord = c("Species", "Sepal.Length"),
decreasing = c(FALSE, TRUE))
#> Species Sepal.Length Sepal.Width
#> 20 setosa 5.1 3.8
#> 5 setosa 5.0 3.6
#> 36 setosa 5.0 3.2
#> 48 setosa 4.6 3.2
#> 74 versicolor 6.1 2.8
#> 136 virginica 7.7 3.0
#> 140 virginica 6.9 3.1
#> 146 virginica 6.7 3.0
#> 104 virginica 6.3 2.9
#> 107 virginica 4.9 2.5
# Natural sorting of character vectors
x <- c("A1", "A10", "A2")
sortX(x, method = "mixed")
#> [1] "A1" "A2" "A10"
# Factor: sort by label (default) vs. level order
sortX(d.frm, ord = "Species") # by label
#> Species Sepal.Length Sepal.Width
#> 5 setosa 5.0 3.6
#> 36 setosa 5.0 3.2
#> 20 setosa 5.1 3.8
#> 48 setosa 4.6 3.2
#> 74 versicolor 6.1 2.8
#> 140 virginica 6.9 3.1
#> 107 virginica 4.9 2.5
#> 136 virginica 7.7 3.0
#> 104 virginica 6.3 2.9
#> 146 virginica 6.7 3.0
sortX(d.frm, ord = "Species", factorsAsCharacter = FALSE) # by level
#> Species Sepal.Length Sepal.Width
#> 5 setosa 5.0 3.6
#> 36 setosa 5.0 3.2
#> 20 setosa 5.1 3.8
#> 48 setosa 4.6 3.2
#> 74 versicolor 6.1 2.8
#> 140 virginica 6.9 3.1
#> 107 virginica 4.9 2.5
#> 136 virginica 7.7 3.0
#> 104 virginica 6.3 2.9
#> 146 virginica 6.7 3.0
# Tables: sort by column 2 descending
tab <- HairEyeColor[, , 1]
sortX(tab, ord = 2L, decreasing = TRUE)
#> Eye
#> Hair Brown Blue Hazel Green
#> Brown 53 50 25 15
#> Blond 3 30 5 8
#> Black 32 11 10 3
#> Red 10 10 7 7
# Tables: sort by marginal row sums
sortX(tab, ord = ncol(tab) + 1L, decreasing = TRUE)
#> Eye
#> Hair Brown Blue Hazel Green
#> Brown 53 50 25 15
#> Black 32 11 10 3
#> Blond 3 30 5 8
#> Red 10 10 7 7
# Sort by row names (always pass 0 as integer)
sortX(tab, ord = 0L)
#> Eye
#> Hair Brown Blue Hazel Green
#> Black 32 11 10 3
#> Blond 3 30 5 8
#> Brown 53 50 25 15
#> Red 10 10 7 7