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#### Logical Sparse Matrices in triplet format

### contains = "lsparseMatrix"
###             ============= ---> superclass methods in ./lsparseMatrix.R


setAs("lgTMatrix", "matrix", # go via fast C code:
      function(from) as(as(from, "lgCMatrix"), "matrix"))

setAs("matrix", "lgTMatrix",
      function(from) {
      stopifnot(is.logical(from))
      if(any(is.na(from)))
          warning("'NA's coerced to 'FALSE' in coercion to logical sparse")
      ij <- which(from, arr.ind = TRUE) - 1:1
      if(length(ij) == 0) ij <- matrix(ij, 0, 2)
      new("lgTMatrix",
          i = ij[,1],
          j = ij[,2],
          Dim = as.integer(dim(from)),
          Dimnames = .M.DN(from))
      })

setAs("lgTMatrix", "dgTMatrix",
      function(from)
      ## more efficient than
      ## as(as(as(sM, "lgCMatrix"), "dgCMatrix"), "dgTMatrix")
      new("dgTMatrix", i = from@i, j = from@j,
          x = rep.int(1, length(from@i)),
          ## cannot copy factors, but can we use them?
          Dim = from@Dim, Dimnames= from@Dimnames))

setMethod("t", signature(x = "lgTMatrix"),
      function(x) new("lgTMatrix", i = x@j, j = x@i,
              Dim = x@Dim[2:1],
              Dimnames= x@Dimnames[2:1]),
      valueClass = "lgTMatrix")