PTXQC (version 1.0.4)

correctSetSize: Re-estimate a new set size to split a number of items into equally sized sets.

Description

This is useful for plotting large datasets where multiple pages are needed. E.g. you know that you need 101 barplots, but you only want to fit about 25 per page. Naively one would now do five plots, with the last one only containing a single barplot. Using this function with correctSetSize(101, 25) would tell you to use 26 barplots per page, so you end up with four plots, all roughly equally filled. It also works the other extreme case, where your initial size is chosen slightly too high, e.g. Sets of size 5 for just 8 items is too much, because we can reduce the set size to 4 and still need two sets but now they are much more equally filled (correctSetSize(8, 5) == 4).

Usage

correctSetSize(item_count, initial_set_size)

Arguments

item_count

Known number of items which need to assigned to sets

initial_set_size

Desired number of items a single set should hold

Value

re-estimated set size which a set should hold in order to avoid underfilled sets

Details

We allow for up to set sizes of 150% from default, to avoid the last set being sparse (we remove it and distribute to the other bins) 150 Once the number of sets is fixed, we distribute all items equally.

E.g. 6 items & initial_set_size=5, would result in 2 bins (5 items, 1 item), but we'd rather have one bin of 6 items or 8 items & initial_set_size=5, would result in 2 bins (5+3 items), since the last set is more than half full, but we'd rather have 4+4

Examples

# NOT RUN {
 stopifnot(
   correctSetSize(8, 5) == 4
 )
 stopifnot(
   correctSetSize(101, 25) == 26
 )
 
# }