Extract tables from a file
extract_tables(
file,
pages = NULL,
area = NULL,
columns = NULL,
col_names = TRUE,
guess = TRUE,
method = c("decide", "lattice", "stream"),
output = c("tibble", "matrix", "character", "asis", "csv", "tsv", "json"),
outdir = NULL,
password = NULL,
encoding = NULL,
copy = FALSE,
...
)
By default, a list of character matrices. This can be changed by specifying an alternative value of method
(see Details).
A character string specifying the path or URL to a PDF file.
An optional integer vector specifying pages to extract from.
An optional list, of length equal to the number of pages specified, where each entry contains a four-element numeric vector of coordinates (top,left,bottom,right) containing the table for the corresponding page. As a convenience, a list of length 1 can be used to extract the same area from all (specified) pages. Only specify area
or columns
. Warning: area
is ignored if guess
is TRUE
.
An optional list, of length equal to the number of pages specified, where each entry contains a numeric vector of horizontal (x) coordinates separating columns of data for the corresponding page. As a convenience, a list of length 1 can be used to specify the same columns for all (specified) pages. Only specify area
or columns
. Warning: columns
is ignored if guess
is TRUE
.
A logical indicating whether to include column names in the output tibbles. Default is TRUE
.
A logical indicating whether to guess the locations of tables on each page. If FALSE
, area
or columns
must be specified; if TRUE
, area
and columns
are ignored.
A string identifying the preferred method of table extraction.
method = "decide"
(default) automatically decide (for each page) whether spreadsheet-like formatting is present and "lattice" is appropriate
method = "lattice"
use Tabula's spreadsheet extraction algorithm
method = "stream"
use Tabula's basic extraction algorithm
A function to coerce the Java response object (a Java ArrayList of Tabula Tables) to some output format. The default method, “matrices”, returns a list of character matrices. See Details for other options.
Output directory for files if output
is set to
"csv"
, "tsv"
or "json"
, ignored otherwise. If equals
NULL
(default), uses R sessions temporary directory tempdir()
.
Optionally, a character string containing a user password to access a secured PDF.
Optionally, a character string specifying an encoding for the text, to be passed to the assignment method of Encoding
.
Specifies whether the original local file(s) should be copied to
tempdir()
before processing. FALSE
by default. The argument is
ignored if file
is URL.
These are additional arguments passed to the internal functions dispatched by method
.
Thomas J. Leeper <thosjleeper@gmail.com>, Tom Paskhalis <tpaskhalis@gmail.com>
This function mimics the behavior of the Tabula command line utility. It returns a list of R character matrices containing tables extracted from a file by default. This response behavior can be changed by using the following options.
output = "tibble"
attempts to coerce the structure returned by method = "character"
into a list of tibbles and returns character strings where this fails.
output = "character"
returns a list of single-element character vectors, where each vector is a tab-delimited, line-separate string of concatenated table cells.
output = "csv"
writes the tables to comma-separated (CSV) files using Tabula's CSVWriter method in the same directory as the original PDF. method = "tsv"
does the same but with tab-separated (TSV) files using Tabula's TSVWriter and method = "json"
does the same using Tabula's JSONWriter method. Any of these three methods return the path to the directory containing the extract table files.
output = "asis"
returns the Java object reference, which can be useful for debugging or for writing a custom parser.
extract_areas
implements this functionality in an interactive mode allowing the user to specify extraction areas for each page.
extract_areas
, get_page_dims
, make_thumbnails
, split_pdf
# simple demo file
f <- system.file("examples", "mtcars.pdf", package = "tabulapdf")
# extract tables from only second page
extract_tables(f, pages = 2)
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