Reads Excel tables (Office 2007+) from a workbook.
# S4 method for workbook,numeric
readTable(object, sheet, table, header, rownames, colTypes, forceConversion,
dateTimeFormat, check.names, useCachedValues, keep, drop, simplify, readStrategy)
# S4 method for workbook,character
readTable(object, sheet, table, header, rownames, colTypes, forceConversion,
dateTimeFormat, check.names, useCachedValues, keep, drop, simplify, readStrategy)
The workbook to use
The index or name of the worksheet on which to look for the specified table
The name of the table to read
The argument header specifies if the first row
should be interpreted as column names. The default value is TRUE.
Index (numeric) or name (character) of column that
should be used as row names. The corresponding column will be removed from the data
set. Defaults to NULL which means that no row names are applied.
Column types to use when reading in the data. Specified as a character
vector of the corresponding type names (see XLC; XLC$DATA_TYPE.<?>). You
may also use R class names such as numeric, character, logical and POSIXt.
The types are applied in the given order to the columns - elements are recycled if necessary.
Defaults to character(0) meaning that column types are determined automatically (see the
Note section for more information).
By default, type conversions are only applied if the specified column type is a more generic type
(e.g. from Numeric to String) - otherwise NA is returned. The forceConversion flag can be
set to force conversion into less generic types where possible.
logical specifying if conversions to less generic types should be
forced. Defaults to FALSE meaning that if a column is specified
to be of a certain type via the colTypes argument and a more generic type is detected in
the column, then NA will be returned (example: column is specified to be DateTime but a
more generic String is found). Specifying forceConversion = TRUE will try to enforce a
conversion - if it succeeds the corresponding (converted) value will be returned, otherwise
NA. See the Note section for some additional information.
Date/time format used when doing date/time conversions. Defaults to
getOption("XLConnect.dateTimeFormat"). This should be a POSIX format specifier according
to strptime although not all specifications have been implemented yet - the most
important ones however are available.
logical specifying if column names of the resulting data.frame
should be checked to ensure that they are syntactically valid valid variable names and are not
duplicated. See the check.names argument of data.frame. Defaults to TRUE.
logical specifying whether to read cached formula results from the
workbook instead of re-evaluating them. This is particularly helpful in cases for reading data
produced by Excel features not supported in XLConnect like references to external workbooks.
Defaults to FALSE, which means that formulas will be evaluated by XLConnect.
List of column names or indices to be kept in the output data frame.
It is possible to specify either keep or drop, but not both at the same time.
Defaults to NULL. If a vector is passed as argument, it will be wrapped into a list.
This list gets replicated to match the length of the other arguments.
List of column names or indices to be dropped in the output data frame.
It is possible to specify either keep or drop, but not both at the same time.
Defaults to NULL. If a vector is passed as argument, it will be wrapped into a list.
This list gets replicated to match the length of the other arguments.
logical specifying if the result should be simplified, e.g. in case the data.frame
would only have one row or one column (and data types match). Simplifying here is identical to calling unlist
on the otherwise resulting data.frame (using use.names = FALSE). The default is FALSE.
character specifying the reading strategy to use. Currently supported strategies are:
"default" (default): Can handle all supported data types incl. date/time values and can deal
directly with missing value identifiers (see setMissingValue)
"fast": Increased read performance. Date/time values are read as numeric (number of days since 1900-01-01;
fractional days represent hours, minutes, and seconds) and only blank cells are recognized as missing (missing value
identifiers as set in setMissingValue are ignored)
Martin Studer
Mirai Solutions GmbH https://mirai-solutions.ch
Overview of Excel tables
https://support.microsoft.com/en-us/office/overview-of-excel-tables-7ab0bb7d-3a9e-4b56-a3c9-6c94334e492c?ocmsassetid=ha010048546&correlationid=ecf0d51a-596f-42e5-9c05-8653648bb180&ui=en-us&rs=en-us&ad=us
workbook,
readNamedRegion,
readWorksheet,
writeNamedRegion,
writeWorksheet,
readNamedRegionFromFile,
onErrorCell
if (FALSE) {
# mtcars xlsx file from demoFiles subfolder of package XLConnect
demoExcelFile <- system.file("demoFiles/mtcars.xlsx", package = "XLConnect")
# Load workbook
wb <- loadWorkbook(demoExcelFile)
# Read table 'MtcarsTable' from sheet 'mtcars_table'
data <- readTable(wb, sheet = "mtcars_table", table = "MtcarsTable")
}
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