library(Matrix) #### Read / Write (sparse) Matrix objects ---------------------- ### Rebuild the 'mm' example matrix, now in KNex data ### This is no longer really important, as we now use ### ../data/KNex.R which creates the S4 object *every time* data(KNex) ## recreate 'mm' from list : sNms <- c("Dim", "i","p","x") L <- lapply(sNms, function(SN) slot(KNex$mm, SN)); names(L) <- sNms mm2 <- new(class(KNex$mm)) for (n in sNms) slot(mm2, n) <- L[[n]] stopifnot(validObject(mm2), identical(mm2, KNex$mm)) L$y <- KNex$y ## save(L, file = "/u/maechler/R/Pkgs/Matrix/inst/external/KNex_slots.rda") ## recreate 'mm' from ASCI file : mmT <- as(KNex$mm, "dgTMatrix") str(mmT) mm3 <- cbind(i = mmT@i, j = mmT@j, x = mmT@x) write.table(mm3, file = "mm-Matrix.tab", row.names=FALSE)# -> ASCII version str(mmr <- read.table("mm-Matrix.tab", header = TRUE)) mmr$i <- as.integer(mmr$i) mmr$j <- as.integer(mmr$j) mmN <- with(mmr, new("dgTMatrix", Dim = c(max(i)+1:1,max(j)+1:1), i = i, j = j, x = x)) stopifnot(identical(mmT, mmN)) # !! ## weaker (and hence TRUE too): stopifnot(all.equal(as(mmN, "matrix"), as(mmT, "matrix"), tol=0)) mm <- as(mmN, "dgCMatrix") stopifnot(all.equal(mm, KNex$mm)) ## save(mm, file = "....../Matrix/data/mm.rda", compress = TRUE) A <- Matrix(c(1,0,3,0,0,5), 10, 10, sparse = TRUE) # warning about [6] vs [10] (fname <- file.path(tempdir(), "kk.mm")) writeMM(A, fname) (B <- readMM(fname)) validObject(B) Bc <- as(B, "CsparseMatrix") stopifnot(identical(A, Bc))