This post assumes you have Git set up in an RStudio project and that you have a basic idea what Git is for. If not, start back at the post Time to Grow Up and Use Git. Once you have an RStudio project set up with Git support, come back here.
esc package requires another, much larger R package called
data.table. That package, however, wouldn’t install. Like many R packages,
data.table required the installation to do an automatic compilation of code written in C, but the C compiler couldn’t find some of the files it needed. This is because Amazon Linux uses non-standard folder locations for many of those files.
I’ve been having problems with the web version of the Open-Meta app crashing with a
C stack usage error. I entered an issue on the Shiny Server Github page and with the help of others who have had this problem, now suspect that the error is caused by the rJava package, which is required by mailR, the package I’ve been using to send email.
observeEvent() handler for all your button and anchor clicks. This week I needed disabled buttons, which are easy to do visually by adding the Bootstrap
disabled class to the button. But the buttons still responded to being clicked.
MySQL provides an external program called mysqldump that writes a file full of MySQL syntax statements that will recreate a database’s tables and their contents. Back in the Apple II days this kind of file was called an exec file. Windows calls them batch files and Linux calls them shell scripts, of which one common format is the bash file. You can create the same thing with HeidiSQL by right-clicking on the database you want to save or duplicate and selecting Export database as SQL.
Who knew? I thought the difference between
&& for ANDing logical vectors in R was just that
& evaluated the whole expression while
&& started at the left and went right until it hit a
FALSE value. But there’s more.
& is vectorized, but
&& only considers the first value in a vector and only returns a single value.
Today I created a new instance for the open-meta.org app on Amazon. Mostly this was to add the RCurl package to R, which I needed to access the PubMed utilities online now that they require
https:// rather than
The Tidyverse is a collection of related R packages, many of which I use on Open-Meta. I recently added the entire Tidyverse to my Windows-based development system, which meant I had to do the same to move that code to my Amazon Lightsail instance, which I did yesterday.
invalidateLater() function, if you know about it at all, probably doesn’t work the way you think it does. Moreover, the way it actually does work, it turns out, is way cooler than the way it appears to work!
<a id="xxx">). Anchor tags are typically used to create links and include an href attribute that holds the URL of the linked document.