parseJob: Parses a collection of elements into (almost) equal-sized...
In Smisc: Sego Miscellaneous

Description Usage Arguments Value Author(s) Examples

Parses a collection of elements into (almost) equal-sized groups. Useful for splitting up an R job that operates over a large dataframe or list into multiple jobs.

1 2	parseJob(n, njobs, collate = FALSE, random.seed = NULL, text.to.eval = FALSE)

`n`	The number elements to be parsed
`njobs`	The number of groups
`collate`	`= TRUE` alternative ordering of the grouping. See example below.
`random.seed`	An integer setting the random seed, which will result in randomizing the elements among the jobs. If `NULL`, no randomization is performed. Randomization cannot be performed if `collate = TRUE` or if `text.to.eval = TRUE`. Randomization is useful when the computing time for each element varies significantly because it helps to even out the run times of parallel jobs.
`text.to.eval`	If `= TRUE`, a text expression is returned, that when evaluated, will produce the sequence of elements for that group. This is especially useful when `n` is very large. (See `Value` section below).

When text.to.eval = FALSE, a list with njobs elements is returned, each element containing a numeric vector of the element numbers which correspond to that group. When text.to.eval = TRUE, a list with njobs elements is returned, each element containing text (let's call it val), that when evaluated using eval(parse(text = val)), will produce the sequence of numbers corresponding to the group.

Landon Sego

x <- parseJob(29, 6)
print(x)

# To see the range of each group
lapply(x, range)

# To see the length of each group
lengths(x)

# Randomize the outcome
parseJob(32, 5, random.seed = 231)

# Example of 'text.to.eval = TRUE'
out <- parseJob(11, 3, text.to.eval = TRUE)
out
lapply(out, function(x) eval(parse(text = x)))

# Example of 'collate = TRUE' and 'text.to.eval = TRUE'
parseJob(11, 3, collate = TRUE)
parseJob(11, 3, collate = TRUE, text.to.eval = TRUE)