convert incidence matrix to list
im2list(x, empty = c(NA, "", 0, FALSE), ...)matrix or equivalent object with colnames(x) indicating
list set names, and rownames(x) indicating list contents.
character vector of incidence matrix values that
should be considered "empty" and therefore do not indicate
the row in x is present for the given column in x.
All other items are considered to be present.
additional arguments are ignored.
list of character vectors, where list names
are defined by colnames(x), and list elements are vectors
that contain values from rownames(x).
This function converts an incidence matrix, or equivalent
data.frame, to a list. The matrix should contain either
numeric values such as c(0, 1), or logical values such
as c(TRUE,FALSE), otherwise values are considered either
zero == FALSE, or non-zero == TRUE.
The resulting list will be named by colnames(x) of the input,
and will contain members named by rownames(x) which are
either non-zero, or contain TRUE.
Values of NA are converted to zero 0 and therefore ignored.
Other jam list functions:
colors_from_list(),
im2list_dep(),
imSigned2list_dep(),
imSigned2list(),
list2concordance(),
list2imSigned(),
list2im()
im <- matrix(c(0,1,-1,1,1,NA,-1,0,1),
ncol=3,
nrow=3,
dimnames=list(letters[1:3], LETTERS[1:3]))
print(im);
#> A B C
#> a 0 1 -1
#> b 1 1 0
#> c -1 NA 1
# matrix input
im2list(im);
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
#> $A
#> [1] "b" "c"
#>
#> $B
#> [1] "a" "b"
#>
#> $C
#> [1] "a" "c"
#>
# data.frame
imdf <- data.frame(im);
print(imdf);
#> A B C
#> a 0 1 -1
#> b 1 1 0
#> c -1 NA 1
im2list(im);
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
#> Warning: NAs introduced by coercion
#> $A
#> [1] "b" "c"
#>
#> $B
#> [1] "a" "b"
#>
#> $C
#> [1] "a" "c"
#>
# logical input
imtf <- (!im == 0);
print(imtf);
#> A B C
#> a FALSE TRUE TRUE
#> b TRUE TRUE FALSE
#> c TRUE NA TRUE
im2list(imtf);
#> $A
#> [1] "b" "c"
#>
#> $B
#> [1] "a" "b"
#>
#> $C
#> [1] "a" "c"
#>