| Type: | Package |
| Title: | A Unified Framework for Input-Output Operations in R |
| Version: | 0.3.2 |
| Date: | 2019-12-16 |
| Author: | David J. H. Shih |
| Maintainer: | David J. H. Shih <djh.shih@gmail.com> |
| Description: | One function to read files. One function to write files. One function to direct plots to screen or file. Automatic file format inference and directory structure creation. |
| Imports: | stringr |
| Depends: | filenamer |
| Suggests: | XML (≥ 3.98-1.1), rhdf5 (≥ 2.26.1), yaml (≥ 2.1.13), jsonlite (≥ 0.9.14), testthat |
| URL: | https://bitbucket.org/djhshih/io |
| BugReports: | https://bitbucket.org/djhshih/io/issues |
| License: | GPL (≥ 3) |
| RoxygenNote: | 7.0.2 |
| NeedsCompilation: | no |
| Packaged: | 2019-12-17 03:01:52 UTC; davids |
| Repository: | CRAN |
| Date/Publication: | 2019-12-17 07:00:03 UTC |
A unified framework for input-output operations in R
Description
io provides qread for reading in data of various types
and qwrite for writing data to files of various types.
Input or output file types can be inferred from filename extensions or
specified explicity.
Details
Use link{io_supported} to check wehather a data or file type is
supported.
Both qread and qwrite can be readily extended
to support additional types by defining specific S3 methods.
Additionally, qdraw offers a unified interface for plotting
to screen or various file formats.
Determine input-output support for data or file type
Description
This function returns whether a type is supported by
qread or qwrite.
Usage
io_supported(type)
Arguments
type |
data or file type |
Value
a data.frame with logical entries;
TRUE if type is supported, FALSE otherwise
Examples
io_supported("rds")
List the files in a directory.
Description
This function extends list.files
by excluding the listing of directories.
Usage
list_files(path = ".", full.names = FALSE, ...)
Arguments
path |
a character vector of path names |
full.names |
whether to return absolute paths |
... |
other arguments passed to |
Value
a character vector of only names of files
Examples
list.files(R.home())
list_files(R.home())
Draw plot
Description
This funtion draws a plot to screen, a file, or both.
Usage
qdraw(
expr,
file = NULL,
device = getOption("plot.device"),
width = NULL,
height = NULL,
aspect.ratio = NULL,
units = NULL,
res = NULL,
mkpath = TRUE,
symlink = TRUE,
...
)
Arguments
expr |
expression for plotting |
file |
filename |
device |
plot device |
width |
plot width [default: 5] |
height |
plot height [default: 5] |
aspect.ratio |
ratio of width to height |
units |
unit of plot dimension [default: "in"] |
res |
bitmap resolution, used only by bitmap formats [default: 300] |
mkpath |
whether to create parent directories (if they do not already exists) |
symlink |
whether to create a symlink to file with a simplified
filename (ignored if file is not a |
... |
other arguments passed to the plot device function |
Details
To send the plot to screen, set device to NA (default).
Optionally, to print the plot on screen to a file, specify file.
If device is NULL, the plot will be sent directly to the
the specified file using a printing device inferred from the file
extension (no graphical window will open).
Set the global option plot.device to affect multiple plots.
Graphical parameters including width, height, res,
units are obtained from the global option getOption("plot").
Examples
## Not run:
# Set device to jpeg (remember to update file extensions for printed plots)
options(plot.device=jpeg)
qdraw(plot(1:10), "plot.jpeg")
# Enable automatic plot format inference
options(plot.device=NULL)
# Plot directly to file (format is inferred from filename extension)
qdraw(plot(1:10), "plot.pdf")
# Plot to screen, then print to file (display will not be closed)
qdraw(plot(1:10), "plot.png", device=NA)
# If an error occurs, be sure to clear the current plot
dev.off()
# or clear all plots
graphics.off()
## End(Not run)
Data input
Description
This function reads a file in a specified format.
Usage
qread(file, type = NULL, ...)
Arguments
file |
file name (character or |
type |
data or file type |
... |
other arguments passed to the underlying function |
Details
If type is NULL, the file type is inferred from
the file extension.
Use io_supported to check support for a file or data type.
Value
a data object (type depends on the underlying function)
Examples
## Not run:
data(cars)
# write data to an RDS file
qwrite(cars, "cars.rds")
# infer output type based on the class of the cars object
qwrite(cars, "cars.dfm", type=NA)
# read data back in
x1 <- qread("cars.rds")
# specify the type explicitly
x3 <- qread("cars.dfm", type="data.frame")
# read all files (with extension) in current directory
xs <- qread(".", pattern="cars")
## End(Not run)
Data output
Description
This function writes an object to file in a specified format.
Usage
qwrite(x, file, type = NULL, mkpath = TRUE, symlink = TRUE, ...)
Arguments
x |
data object to write |
file |
filename (character or |
type |
data or file type |
mkpath |
whether to create parent directories (if they do not already exists) |
symlink |
whether to create a symlink to file with a simplified
file name (ignored if file is not a |
... |
other arguments passed to the underlying function |
Details
If type is NULL, the file type is inferred from
the file extension. If type is NA or if the file extension is
unavailable or unknown, type is inferred from class(x).
Use io_supported to check support for a file or data type.
Value
a data object (object type depends on the underlying function)
Examples
## Not run:
data(cars)
# write data to a TSV file
qwrite(cars, "cars.tsv")
# infer output type based on the class of the cars object
qwrite(as.matrix(cars), "cars.mtx", type=NA)
## End(Not run)