compress_rows.data.frame {statnet.common}

"Compress" a data frame.

Description

compress_rows.data.frame "compresses" a data frame, returning unique rows and a tally of the number of times each row is repeated, as well as a permutation vector that can reconstruct the original data frame. decompress_rows.compressed_rows_df reconstructs the original data frame.

Usage

## S3 method for class 'data.frame'
compress_rows(x, ...)

## S3 method for class 'compressed_rows_df'
decompress_rows(x, ...)

Arguments

x

For compress_rows.data.frame a data.frame to be compressed. For decompress_rows.compress_rows_df a list as returned by compress_rows.data.frame.

...

Additional arguments, currently unused.

Value

For compress_rows.data.frame, a list with three elements:

rows

Unique rows of x

frequencies

A vector of the same length as the number or rows, giving the number of times the corresponding row is repeated

ordering

A vector such that if c is the compressed data frame, c$rows[c$ordering,,drop=FALSE] equals the original data frame, except for row names

rownames

Row names of x

For decompress_rows.compressed_rows_df, the original data frame.

See Also

data.frame

Examples

(x <- data.frame(V1=sample.int(3,30,replace=TRUE),
                 V2=sample.int(2,30,replace=TRUE),
                 V3=sample.int(4,30,replace=TRUE)))

(c <- compress_rows(x))

stopifnot(all(decompress_rows(c)==x))