bigmemory (version 2.3)

bigmemory-package: bigmemory: massive matrices in (possibly shared) memory.

Description

bigmemory implements massive matricies in C++ (optionally, in shared memory) and supports their basic manipulation and exploration. Access to and manipulation of a big.matrix object is exposed in R by an S4 class whose interface is simlar to an R matrix.

Details

ll{ Package: bigmemory Type: Package Version: 2.3 Date: 2008-07-26 License: LGPL-3 } Multi-gigabyte data sets challenge and frustrate R users even on well-equipped hardware. C/C++ or Fortran programming can be helpful, but is cumbersome for interactive data analysis and lacks the flexibility and power of R's rich statistical programming environment. The new package bigmemory bridges this gap, implementing massive matrices in memory (managed in R but implemented in C++) and supporting their basic manipulation and exploration. It is ideal for problems involving the analysis in R of manageable subsets of the data,or when an analysis is conducted mostly in C++. In a Unix environment, the data structure may be allocated to shared memory with transparent read and write locking, allowing separate R processes on the same computer to share access to a single copy of the data set. This opens the door for more powerful parallel analyses and data mining of massive data sets.

References

See http://www.stat.yale.edu/~jay/bigmemory.

See Also

big.matrix, mwhich, colmean, biglm

Examples

# Our examples are all trivial in size, rather than burning huge amounts
# of memory simply to demonstrate the package functionality.

x <- big.matrix(5, 2, type="integer", init=0)
colnames(x)=c("alpha", "beta")
x
x[,]
x[,1] <- 1:5
x[,]
mean(x)
colmean(x)
summary(x)