In RSPaW/RSSApkg: Utility functions for remote sensing and spatial analysis work

Time for a change

Having scripts or code that perform elements of processing or analysis is an essential step in making our work robust and repeatable. However not having control of individual function versions when copied from one work project to the next becomes problematic on many levels:

1. Copied and pasted functions can inadvertently introduce errors.
2. Old buggy versions persist when new and improved versions are released.
3. It becomes harder to fix bugs when the internal code of a function has been altered beyond its original remit.

So in light of this it's time to release the Remote Sensing and Spatial Analysis section's own software package, RSSApkg.

A Package?

This is a great strength of R and enables us to wrap up individual functions with associated help files and "How To" vignettes in an easily distributable and versioned bundle. Think of a package as a "toolbox" that contains a whole heap of interrelated tools that can be used on a task. Even if you are a casual user of R you will have come into contact with packages every time you run a library() command at the top of a script.

The benefits of our package will be:

1. There is loads of help documentation including:
   • function help files when working in R Studio or R.
   • a package website with help files and workflow vignettes.
2. You will always have access to the most up to date version of bug free functions.
3. All commonly used functions are readily accessible without having to remember where you last worked with a script and then having to copy it.
4. Processing/analysis scripts (you will still save these for a project so that you can repeat it again) will be shorter and easy to read.
5. New functions as they become mature will be added.

Let me at it!

If you are using R Studio on the server then it is already installed you just need to load it.

library(RSSApkg)

If you are working on your own computer then you may need to install it first. The package is only available to install from the RSSA's own Git Hub project (yes that's right we have our own!) and to download it you need another package to help with this.

#install devtools from CRAN if you don't already have it
install.packages("devtools")

#install and load RSSApkg
devtools::install_github("RSPaW/RSSApkg")
library(RSSApkg)

I will always send around an email heads up if the package has been updated and let you know what's changed. If you are working on the server then its just nice to know. If however you like working on your own computer then it's your cue to re-install with the method outlined above.

Easy huh?

Finding Help

As previously mentioned there is help available for all the functions in the package.

1. From the console or editor

If you know the name of the function you want help with, in the console window type help("function name"). This will open the help file for that function and if working in R Studio, will open it in the help pane.

Another great feature in R Studio is that there is an auto-complete so when typing out the function name it will try to guess the function name and show what the function arguments are.

2. Using RStudio's help

Firstly click on the Packages tab and scroll down the available packages until you find the RSSApkg.

This has the benefit of showing you all the help files available. Next you click on the one you want.

Detailed documentation is then displayed.

3. From the website

Housing and distributing packages from Git Hub has a nice side benefit and that is that a package website can easily be created. There are a number of ways to get to it. You can click here and there is always a link at the bottom of the help files accessed via the two methods outlined above. The benefits of the website are:

1. All documentation relating to the package resides in the one readily accessible location. This will include:
   • Help files like those explained above located under the Reference menu.
   • Package vignettes. These vignettes are like guided "How To" documents. Vignettes are written for complicated functions with multiple side effects or detailed workflows involving multiple functions and are found under the Articles menu.
2. There is a landing page giving instructions on installation and loading the package.
3. There are links to the source code and a place to log bugs or issues. Please use the later if you obtain anything other than what you expect when using the package.
4. You can see who the developers, authors and maintainers are.
5. You can see the build status (pass/fail) for Windows or Linux/Mac OS.
6. Lastly there will also be a News menu that will outline version differences and additions to the package over time.

RSPaW/RSSApkg documentation built on May 21, 2019, 1:41 a.m.