tidy_xlsx: Import xlsx (Excel) cell contents into a tidy structure.

Description

tidy_xlsx() is deprecated. Please use xlsx_cells() or xlsx_formats() instead.

tidy_xlsx() imports data from spreadsheets without coercing it into a rectangle. Each cell is represented by a row in a data frame, giving the cell's address, contents, formula, height, width, and keys to look up the cell's formatting in an adjacent data structure within the list returned by this function.

Usage

tidy_xlsx(path, sheets = NA)

Value

A list of the data within each sheet ($data), and the formatting applied to each cell ($formats).

Each sheet's data is returned as a data frames, one per sheet, by the sheet name. For example, the data in a sheet named 'My Worksheet' is in x$data$My Worksheet. Each data frame has the following columns:

address The cell address in A1 notation.
row The row number of a cell address (integer).
col The column number of a cell address (integer).
is_blank Whether or not the cell has a value
data_type The type of a cell, referring to the following columns: error, logical, numeric, date, character, blank.
error The error value of a cell.
logical The boolean value of a cell.
numeric The numeric value of a cell.
date The date value of a cell.
character The string value of a cell.
character_formatted A data frame of substrings and their individual formatting.
formula The formula in a cell (see 'Details').
is_array Whether or not the formula is an array formula.
formula_ref The address of a range of cells group to which an array formula or shared formula applies (see 'Details').
formula_group The formula group to which the cell belongs (see 'Details').
comment The text of a comment attached to a cell.
height The height of a cell's row, in Excel's units.
width The width of a cell's column, in Excel's units.
style_format An index into a table of style formats x$formats$style (see 'Details').
local_format_id An index into a table of local cell formats x$formats$local (see 'Details').

Formula

When a cell has a formula, the value in the 'content' column is the result of the formula the last time it was evaluated.

Certain groups of cells may share a formula that differs only by addresses referred to in the formula; such groups are identified by an index, the 'formula_group'. The xlsx (Excel) file format only records the formula against one cell in any group. xlsx_cells() propagates such formulas to the other cells in a group, making the necessary changes to relative addresses in the formula.

Array formulas may also apply to a group of cells, identified by an address 'formula_ref', but xlsx (Excel) file format only records the formula against one cell in the group. xlsx_cells() propagates such formulas to the other cells in a group. Unlike shared formulas, no changes to addresses in array formulas are necessary.

Formulas that refer to other workbooks currently do not name the workbooks directly, instead via indices such as [1]. It is planned to dereference these.

Formatting

Cell formatting is returned in x$formats. There are two types or scopes of formatting: 'style' formatting, such as Excel's built-in styles 'normal', 'bad', etc., and 'local' formatting, which overrides particular elements of the style, e.g. by making it bold. Both types of are returned in x$formats$style and x$formats$local, with identical structures. To look up the local formatting of a given cell, take the cell's 'local_format_id' value (x$data$Sheet1[1, "local_format_id"]), and use it as an index into the format structure. E.g. to look up the font size, x$formats$local$font$size[local_format_id]. To see all available formats, type str(x$formats$local).

Colours may be recorded in any of three ways: a hexadecimal RGB string with or without alpha, an 'indexed' colour, and an index into a 'theme'. tidy_xlsx dereferences 'indexed' and 'theme' colours to their hexadecimal RGB string representation, and standardises all RGB strings to have an alpha channel in the first two characters. The 'index' and the 'theme' name are still provided. To filter by an RGB string, you could look up the RGB values in a spreadsheet program (e.g. Excel, LibreOffice, Gnumeric), and use the grDevices::rgb() function to convert these to a hexadecimal string. Put the alpha value in first, e.g.

A <- 1; R <- 0.5; G <- 0; B <- 0
rgb(A, R, G, B)
# [1] "#FF800000"

Strings can be formatted within a cell, so that a single cell can contain substrings with different formatting. This in-cell formatting is available in the column character_formatted, which is a list-column of data frames. Each row of each data frame describes a substring and its formatting. For cells without a character value, character_formatted is NULL, so for further processing you might need to filter out the NULLs first.

Arguments

path: Path to the xlsx file.
sheets: Sheets to read. Either a character vector (the names of the sheets), an integer vector (the positions of the sheets), or NA (default, all sheets).

Details

A cell has two 'values': its content, and sometimes also a formula. It also has formatting applied at the 'style' level, which can be locally overridden.

Content

Depending on the cell, the content may be a numeric value such as 365 or 365.25, it may represent a date/datetime in one of Excel's date/datetime systems, or it may be an index into an internal table of strings. tidy_xlsx() attempts to infer the correct data type of each cell, returning its value in the appropriate column (error, logical, numeric, date, character). In case this cleverness is unhelpful, the unparsed value and type information is available in the 'content' and 'type' columns.

Formula

When a cell has a formula, the value in the 'content' column is the result of the formula the last time it was evaluated.

Certain groups of cells may share a formula that differs only by addresses referred to in the formula; such groups are identified by an index, the 'formula_group'. The xlsx (Excel) file format only records the formula against one cell in any group, but tidy_xlsx() propagates the formula to all the cells in the group, making the necessary changes to relative addresses in the formula.

Array formulas may also apply to a group of cells, identified by an address 'formula_ref', but xlsx (Excel) file format only records the formula against one cell in the group. Unlike ordinary formulas, tidy_xlsx() does not propagate these to the other cells in the group.

Formulas that refer to other workbooks currently do not name the workbooks directly, instead via indices such as [1]. It is planned to dereference these.

Formatting

Cell formatting is returned in x$formats. There are two types of formatting: 'style' formatting, such as Excel's built-in styles 'normal', 'bad', etc., and 'local' formatting, which overrides the style. These are returned in x$formats$style and x$formats$local, with identical structures. To look up the local formatting of a given cell, take the cell's 'local_format_id' value (x$data$Sheet1[1, "local_format_id"]), and use it as an index into the format structure. E.g. to look up the font size, x$formats$local$font$size[local_format_id]. To see all available formats, type str(x$formats$local).

Examples

Run this code

if (FALSE) {
examples <- system.file("extdata/examples.xlsx", package = "tidyxl")

# All sheets
str(tidy_xlsx(examples)$data)

# Specific sheet either by position or by name
str(tidy_xlsx(examples, 2)$data)
str(tidy_xlsx(examples, "Sheet1")$data)

# Data (cell values)
x <- tidy_xlsx(examples)
str(x$data$Sheet1)

# Formatting
str(x$formats$local)

# The formats of particular cells can be retrieved like this:

Sheet1 <- x$data$Sheet1
x$formats$style$font$bold[Sheet1$style_format]
x$formats$local$font$bold[Sheet1$local_format_id]

# To filter for cells of a particular format, first filter the formats to get
# the relevant indices, and then filter the cells by those indices.
bold_indices <- which(x$formats$local$font$bold)
Sheet1[Sheet1$local_format_id %in% bold_indices, ]

# In-cell formatting is available in the `character_formatted` column as a
# data frame, one row per substring.
tidy_xlsx(examples)$data$Sheet1$character_formatted[77]
}

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