pag_indices_inner: Find Pagination Indices From Pagination Info Dataframe

In formatters: ASCII Formatting for Values and Tables

Find Pagination Indices From Pagination Info Dataframe

Description

Pagination methods should typically call the make_row_df method for their object and then call this function on the resulting pagination info data.frame.

Usage

pag_indices_inner(
  pagdf,
  rlpp,
  min_siblings,
  nosplitin = character(),
  verbose = FALSE,
  row = TRUE,
  have_col_fnotes = FALSE,
  div_height = 1L
)

Arguments

pagdf	data.frame. A pagination info data.frame as created by either make_rows_df or make_cols_df.
rlpp	numeric. Maximum number of row lines per page (not including header materials), including (re)printed header and context rows
min_siblings	numeric. Minimum sibling rows which must appear on either side of pagination row for a mid-subtable split to be valid. Defaults to 2.
nosplitin	character. List of names of sub-tables where page-breaks are not allowed, regardless of other considerations. Defaults to none.
verbose	logical(1). Should additional informative messages about the search for pagination breaks be shown. Defaults to FALSE.
row	logical(1). Is pagination happening in row space (TRUE, the default) or column space (FALSE)
have_col_fnotes	logical(1). Does the table-like object being rendered have column-associated referential footnotes.
div_height	numeric(1). The height of the divider line when the associated object is rendered. Defaults to 1.

Details

pab_indices_inner implements the Core Pagination Algorithm for a single direction (vertical if row = TRUE, the default, horizontal otherwise) based on the pagination dataframe and (already adjusted for non-body rows/columns) lines (or characters) per page.

Value

A list containing the vector of row numbers, broken up by page

Pagination Algorithm

Pagination is performed independently in the vertical and horizontal directions based solely on a pagination data.frame, which includes the following information for each row/column:

• number of lines/characters rendering the row will take after word-wrapping (self_extent)

• the indices (reprint_inds) and number of lines (par_extent) of the rows which act as context for the row

• the row's number of siblings and position within its siblings

Given lpp (cpp) already adjusted for rendered elements which are not rows/columns and a dataframe of pagination information, pagination is performed via the following algorithm, and with a start = 1:

Core Pagination Algorithm:

1. Initial guess for pagination point is start + lpp (start + cpp)

2. While the guess is not a valid pagination position, and guess > start, decrement guess and repeat

• an error is thrown if all possible pagination positions between start and start + lpp (start + cpp) would ever be ⁠< start⁠ after decrementing

1. Retain pagination index

2. if pagination point was less than NROW(tt) (ncol(tt)), set start to pos + 1, and repeat steps (1) - (4).

Validating pagination position:

Given an (already adjusted) lpp or cpp value, a pagination is invalid if:

• The rows/columns on the page would take more than (adjusted) lpp lines/cpp characters to render including

  • word-wrapping

  • (vertical only) context repetition

• (vertical only) footnote messages and or section divider lines take up too many lines after rendering rows

• (vertical only) row is a label or content (row-group summary) row

• (vertical only) row at the pagination point has siblings, and it has less than min_siblings preceding or following siblings

• pagination would occur within a sub-table listed in nosplitin

Examples

mypgdf <- basic_pagdf(row.names(mtcars))

paginds <- pag_indices_inner(mypgdf, rlpp = 15, min_siblings = 0)
lapply(paginds, function(x) mtcars[x, ])

formatters documentation built on Aug. 25, 2023, 5:18 p.m.