I/O Operations with Sparse Matrices

Fast 'SVMlight' reader and writer. 'SVMlight' is most commonly used format for storing sparse matrices (possibly with some target variable) on disk. For additional information about 'SVMlight' format see < http://svmlight.joachims.org/>.

sparsio

sparsio is a small (the only dependency is Rcpp) R package for sparse matrices Input/Output. It provides fast svmlight reader and writer.

• read_svmlight()
• write_svmlight()

Quick reference

library(Matrix)
library(sparsio)
N = 1e8
i = sample(1e5, N, T)
j = sample(1e5, N, T)
vals = runif(N)
x = sparseMatrix(i, j, x = vals)
print(object.size(x), units = "Gb")
# 1.1 Gb

y = sample(c(0, 1), nrow(x), replace = TRUE)
f = tempfile(fileext = ".svmlight")
system.time(write_svmlight(x, y, f))
# user  system elapsed 
# 68.014   2.785  70.899

file.size(f)/1e9
# 1.48135 Gb

system.time(x2 <- read_svmlight(f, type = "CsparseMatrix"))
# user  system elapsed 
# 55.021   2.803  57.892

all.equal(x2$x, x)
# "Mean relative difference: 4.636406e-07"
all.equal(x2$y, y)
# TRUE