Blosc is a blocking, shuffling and lossless compression algorithm. It is often used to compress n-dimensional structured array data. It is applied (amongst others) in the geo-spatial zarr file format. This package ports BLOSC compressors and decompressors to R.
Install latest developmental version from R-Universe:
install.packages("blosc", repos = c('https://pepijn-devries.r-universe.dev', 'https://cloud.r-project.org'))
MacOS users may first need to install system requirements before installing the package using:
source("https://mac.R-project.org/bin/install.R")
install.libs("blosc")
The blosc package can be uesd to compress raw
data, but
also vectors of other data types. The example below shows how data from
the volcano matrix can be compressed with blosc.
library(blosc)
<-
volcano_compressed blosc_compress(volcano, typesize = 2L, dtype = "<f2")
object.size(volcano_compressed)
#> 6312 bytes
object.size(volcano)
#> 42672 bytes
Note that 16 bit floating (<f2
) point numbers are
used for the compression which are much less precise than R’s native 64
bit floating point numbers. Nonetheless, in this particular case the
precision is sufficient to restore the volcano data.
<-
volcano_reconstructed matrix(
blosc_decompress(volcano_compressed, dtype = "<f2"),
nrow(volcano),
ncol(volcano)
)
image(volcano_reconstructed, col = terrain.colors(24L))
Big thanks to Simon Urbanek for assisting with setting up the MacOS config.
Please note that the blosc project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.