18Dec 2018 by Andrew Treadway

How to change a file’s last modified date with R

File Manipulation, R
This relatively quick post goes through how to change a file's last modified date with base R. How to change a file's modified time with R Let's say we have a file, test.txt. What if we want to change the last modified date of the file (let's suppose the file's not that important)? Let's say, for instance, we want to make a file have a last modified date back in the 1980's. We can do that with one line of code. First, let's use file.info to check the current modified date of some file called test.txt. We can see above by looking at mtime that this file was last modified December 4th, 2018. Now, we can use a function called Sys.setFileTime to change the modified date to any date including…
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10Dec 2018 by Andrew Treadway
10 R functions for Linux commands and vice-versa

10 R functions for Linux commands and vice-versa

File Manipulation, R, System Administration
This post will go through 10 different Linux commands and their R alternatives. If you're interested in learning more R functions for working with files like some of those below, also check out this post. How to list all the files in a directory Linux R What does it do? ls list.files() Lists all the files in a directory ls -R list.files(recursive = TRUE) Recursively lists all the files in a directory and all sub-directories ls | grep "something" list.files(pattern = "something") Lists all the files in a directory containing the regex "something" R Linux Getting the top records in a file / object Linux R What does it do? head head() Prints the top n records of a file (Linux) / data frame or other object (R) R Linux…
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24Aug 2018 by Andrew Treadway
Getting data from PDFs the easy way with R

Getting data from PDFs the easy way with R

R
Earlier this year, a new package called tabulizer was released in R, which allows you to automatically pull out tables and text from PDFs. Note, this package only works if the PDF's text is highlightable (if it's typed) -- i.e. it won't work for scanned-in PDFs, or image files converted to PDFs. If you don't have tabulizer installed, just run install.packages("tabulizer") to get started. Initial Setup After you have tabulizer installed, we'll load it, and define a variable referencing an example PDF. The PDFs you manipulate with this package don't have to be located on your machine -- you can use tabulizer to reference a PDF by a URL. For our first example, we're going to use a sample PDF file found here: http://www.sedl.org/afterschool/toolkits/science/pdf/ast_sci_data_tables_sample.pdf How to extract all the tables…
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11Jul 2018 by Andrew Treadway
R: How to create, delete, move, and more with files

R: How to create, delete, move, and more with files

File Manipulation, R, System Administration
Though Python is usually thought of over R for doing system administration tasks, R is actually quite useful in this regard. In this post we're going to talk about using R to create, delete, move, and obtain information on files. How to get and change the current working directory Before working with files, it's usually a good idea to first know what directory you're working in. The working directory is the folder that any files you create or refer to without explicitly spelling out the full path fall within. In R, you can figure this out with the getwd function. To change this directory, you can use the aptly named setwd function. Creating Files and Directories A new folder, or directory, can be created in R using the dir.create function,…
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31Aug 2017 by Andrew Treadway
File Manipulation with Python

File Manipulation with Python

File Manipulation, Python, System Administration
Getting started Python is great for automating file creation, deletion, and other types of file manipulations.  Two of the primary packages used to perform these types of tasks are os and shutil.  We'll be covering a few useful highlights from each of these. How to get and change your current working directory You can get your current working directory using os.getcwd: Any actions you take without specifying a directory will be assumed to be associated with your current working directory i.e. if you create or search for a file without specifying a directory, Python will assume you're in the value of os.getcwd(). To change your working directory, use os.chdir: How to merge a directory name with a file name The os package contains a nice method to join together a…
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