R: Import Data Directly From Excel

XLGetRange {DescTools}

R Documentation

Import Data Directly From Excel

Description

The package RDCOMClient is used to open an Excel workbook and return the content (value) of one (or several) given range(s) in a specified sheet. Helpful, if pathologically scattered data on an Excel sheet, which can't simply be saved as CSV-file, has to be imported in R.

XLGetWorkbook does the same for all the sheets in an Excel workbook.

Usage

XLGetRange(file = NULL, sheet = NULL, range = NULL, as.data.frame = TRUE,
           header = FALSE, stringsAsFactors = FALSE, echo = FALSE, datecols = NA,
           na.strings = NULL)

XLGetWorkbook(file, compactareas = TRUE)

Arguments

`file`	the fully specified path and filename of the workbook. If it is left as `NULL`, the function will look for a running Excel-Application and use its current sheet. The parameter `sheet` will be ignored in this case.
`sheet`	the name of the sheet containing the range(s) of interest.
`range`	a scalar or a vector with the address(es) of the range(s) to be returned (characters). Use "A1"-address mode to specify the ranges, for example `"A1:F10"`. If set to `NULL` (which is the default), the function will look for a selection that contains more than one cell. If found, the function will use this selection. If there is no selection then the current region of the selected cell will be used.
`as.data.frame`	logical. Determines if the cellranges should be coerced into data.frames. Defaults to TRUE, as this is probably the common use of this function.
`header`	a logical value indicating whether the range contains the names of the variables as its first line. Default is FALSE. `header` is ignored if `as.data.frame` has been set to FALSE.
`stringsAsFactors`	logical. Should character columns be coerced to factors? The default is FALSE, which will return character vectors.
`echo`	logical. If set to `TRUE`, the function will print the full command used, such that it can be copied into the R-script for future use.
`datecols`	a character or integer vector, defining which columns in Excel are of date type and should directly be converted to Date columns in R. Ignored if `as.data.frame` is `FALSE`.
`na.strings`	a character vector of strings which are to be interpreted as `NA` values. Blank fields are always considered to be missing values. Default is `NULL`, meaning none.
`compactareas`	logical, defining if areas should be returned by `XLGetWorkbook` as list or as matrix (latter is default).

Details

The result consists of a list of lists, if as.data.frame is set to FALSE. Be then prepared to encounter NULL values. Those will prevent from easily being able to coerce the square data structure to a data.frame.

The following code will replace the NULL values by NA and coerce the data to a data.frame.

  # get the range D1:J69 from an excel file
  xlrng <- XLGetRange(file="myfile.xlsx", sheet="Tabelle1",
                      range="D1:J69", as.data.frame=FALSE)

  # replace NULL values by NA
  xlrng[unlist(lapply(xlrng, is.null))] <- NA

  # coerce the square data structure to a data.frame
  d.lka <- data.frame(lapply(data.frame(xlrng), unlist))

This of course can be avoided by setting as.data.frame = TRUE.

The function will return dates as integer values, because XL stores them as integers. An Excel date can be converted with the (unusual) origin of as.Date(myDate, origin="1899-12-30"). See also XLDateToPOSIXct, which does the job. The conversion can be applied directly by using datecols and enumerate date columns in the sheet data.

Value

If as.data.frame is set to TRUE, a single data.frame or a list of data.frames will be returned. If set to FALSE a list of the cell values in the specified Excel range, resp. a list of lists will be returned.

XLGetWorkbook returns a list of lists of the values in the given workbook.

Author(s)

Andri Signorell <andri@signorell.net>

Examples

## Not run:  # Windows-specific example

XLGetRange(file="C:\My Documents\data.xls",
           sheet="Sheet1",
           range=c("A2:B5","M6:X23","C4:D40"))


# if the current region has to be read (incl. a header), place the cursor in the interesting region
# and run:
d.set <- XLGetRange(header=TRUE)

## End(Not run)

[Package DescTools version 0.99.24 Index]