R: Standardize a Sparse Matrix in Triplet Format

asUniqueT {Matrix}

R Documentation

Standardize a Sparse Matrix in Triplet Format

Description

Detect or standardize a TsparseMatrix with unsorted or duplicated (i,j) pairs.

Usage

anyDuplicatedT(x, ...)
isUniqueT(x, byrow = FALSE, isT = is(x, "TsparseMatrix"))
asUniqueT(x, byrow = FALSE, isT = is(x, "TsparseMatrix"))
aggregateT(x)

Arguments

`x`	an R object. `anyDuplicatedT` and `aggregateT` require `x` inheriting from `TsparseMatrix`. `asUniqueT` requires `x` inheriting from `Matrix` and coerces `x` to `TsparseMatrix` if necessary.
`...`	optional arguments passed to the default method for generic function `anyDuplicated`.
`byrow`	a logical indicating if `x` should be sorted by row then by column.
`isT`	a logical indicating if `x` inherits from virtual class `TsparseMatrix`.

Value

anyDuplicatedT(x) returns the index of the first duplicated (i,j) pair in x (0 if there are no duplicated pairs).

isUniqueT(x) returns TRUE if x is a TsparseMatrix with sorted, nonduplicated (i,j) pairs and FALSE otherwise.

asUniqueT(x) returns the unique TsparseMatrix representation of x with sorted, nonduplicated (i,j) pairs. Values corresponding to identical (i,j) pairs are aggregated by addition, where in the logical case “addition” refers to logical OR.

aggregateT(x) aggregates without sorting.

Examples


example("dgTMatrix-class", echo=FALSE)
## -> 'T2'  with (i,j,x) slots of length 5 each
T2u <- asUniqueT(T2)
stopifnot(## They "are" the same (and print the same):
          all.equal(T2, T2u, tol=0),
          ## but not internally:
          anyDuplicatedT(T2)  == 2,
          anyDuplicatedT(T2u) == 0,
          length(T2 @x) == 5,
          length(T2u@x) == 3)

isUniqueT(T2 ) # FALSE
isUniqueT(T2u) # TRUE

T3 <- T2u
T3[1, c(1,3)] <- 10; T3[2, c(1,5)] <- 20
T3u <- asUniqueT(T3)
str(T3u) # sorted in 'j', and within j, sorted in i
stopifnot(isUniqueT(T3u))

## Logical l.TMatrix and n.TMatrix :
(L2 <- T2 > 0)
validObject(L2u <- asUniqueT(L2))
(N2 <- as(L2, "nMatrix"))
validObject(N2u <- asUniqueT(N2))
stopifnot(N2u@i == L2u@i, L2u@i == T2u@i,  N2@i == L2@i, L2@i == T2@i,
          N2u@j == L2u@j, L2u@j == T2u@j,  N2@j == L2@j, L2@j == T2@j)
# now with a nasty NA  [partly failed in Matrix 1.1-5]:
L.0N <- L.1N <- L2
L.0N@x[1:2] <- c(FALSE, NA)
L.1N@x[1:2] <- c(TRUE, NA)
validObject(L.0N)
validObject(L.1N)
(m.0N <- as.matrix(L.0N))
(m.1N <- as.matrix(L.1N))
stopifnot(identical(10L, which(is.na(m.0N))), !anyNA(m.1N))
symnum(m.0N)
symnum(m.1N)