knitr::opts_chunk$set( collapse = TRUE, comment = "#>" )
The logr package helps create log files for R scripts. The package
provides easy logging, without the complexity of other logging systems. It is
designed for analysts who simply want a written log of their program
execution. The package is implemented as a wrapper to
the base R sink()
function.
There are really only three logr functions:
log_open()
log_print()
log_close()
The log_open()
function initiates the log. The
log_print()
function prints an object to the log. The log_close()
function
closes the log. In normal situations, a user would place the call to
log_open()
at the top of the program, call log_print()
as needed in the
program body, and call log_close()
once at the end of the program.
A sample program is as follows:
library(logr) # Create temp file location tmp <- file.path(tempdir(), "test.log") # Open log lf <- log_open(tmp) # Send message to log log_print("High Mileage Cars Subset") # Perform operations hmc <- subset(mtcars, mtcars$mpg > 20) # Print data to log log_print(hmc) # Close log log_close() # View results writeLines(readLines(lf))
You can print to the log anything that you can print to the console: vectors,
lists, and data frames are all valid objects for logging. Under the hood,
logr calls the print()
function on that object, and writes the results
to the log. The log_print()
function, by default, will also print the
object to the console. That means you can replace calls to print()
with
log_print()
, and there will be no loss of convenience during development.
The log created by logr is simpler than most logging packages. This log is designed to be human-readable, and increases the traceability of your activities. There are three main enhancements to a logr log:
Here is an example log, created by the sample program above:
========================================================================= Log Path: C:/Users/dbosa/AppData/Local/Temp/RtmpQtOzhy/log/test.log Working Directory: C:/packages/logr User Name: dbosak R Version: R Under development (unstable) (2020-06-29 r78751) Machine: BOSAK-MAIN x86-64 Operating System: Windows 10 x64 build 18362 Base Packages: stats graphics grDevices utils datasets methods base Other Packages: logr_1.2.7 dplyr_1.0.7 testthat_3.1.0 Log Start Time: 2020-06-30 07:15:52 ========================================================================= High Mileage Cars Subset NOTE: Log Print Time: 2020-06-30 07:15:52 NOTE: Elapsed Time in seconds: 0.0219531059265137 mpg cyl disp hp drat wt qsec vs am gear carb Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4 Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4 Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1 Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1 Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2 Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2 Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1 Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2 Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1 Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1 Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1 Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2 Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2 Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2 NOTE: Data frame has 14 rows and 11 columns. NOTE: Log Print Time: 2020-06-30 07:15:52 NOTE: Elapsed Time in seconds: 0.0508558750152588 ========================================================================= Log End Time: 2020-06-30 07:15:53 Log Elapsed Time: 0 00:00:00 =========================================================================
For addition exploration of the logr package, please read the following articles:
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