tests/write-read.R

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, "TsparseMatrix")
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"), tolerance=0))

mm <- as(mmN, "CsparseMatrix")
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))

fname <- system.file("external", "wrong.mtx", package = "Matrix")
r <- try(readMM(fname))
stopifnot(inherits(r, "try-error"), length(grep("readMM.*row.*1:nr", r)) == 1)
## gave a much less intelligible error message

Try the Matrix package in your browser

Any scripts or data that you put into this service are public.

Matrix documentation built on Nov. 11, 2022, 9:06 a.m.