This lesson is being piloted (Beta version)

Data Harvesting for Agriculture: Instructor Notes

A Note on Our Philosophy

We are targeting working farmers and certified crop advisors (CCAs). We do not and should not expect them to prepare complex analytical codes from scratch on the basis of a two-day workshop. We have instead decided to package much of the analytical logic into a set of functions in functions.R, allowing us to focus on higher-level

We highly recommend finding helpers who can help participants import data from various sources in order to understand how to adapt these tools to their own farm’s working procedures. Augment, don’t displace, their tools.

Workshop Pages

There are some places where our pages still refer to the University of Illinois’ particular setup. These are marked with XXX in HTML comment tags. You should modify these instructions for your own hosting. (Ultimately, these should be replaced with inclusions for Jekyll.)

Setup Instructions

We have found that student setup can take an inordinate amount of time, particularly on Windows machines which require a large download to install R and RStudio. The setup instructions presume that the instructor or host will provide USB drives pre-loaded with the necessary materials for both Windows and Mac machines. (We anticipate a vanishingly small segment of the farming community to be using Linux on their daily machines.)

These USB drives should contain the following, updated for current versions of the packages.

├── DataHarvestingMac
│   ├── PackageTarFiles
│   │   ├── broom_0.5.4.tgz
│   │   ├── data.table_1.12.8.tgz
│   │   ├── daymetr_1.4.tgz
│   │   ├── dplR_1.7.0.tgz
│   │   ├── FedData_2.5.7.tgz
│   │   ├── ggplot2_3.2.1.tgz
│   │   ├── gstat_2.0-4.tgz
│   │   ├── list_of_locations_for_packages.txt
│   │   ├── lubridate_1.7.4.tgz
│   │   ├── measurements_1.4.0.tgz
│   │   ├── raster_3.0-12.tgz
│   │   ├── rgdal_1.4-8.tgz
│   │   ├── sf_0.8-1.tgz
│   │   └── tmap_2.3-2.tgz
│   ├── qgis-macos-pr.dmg
│   ├── R-3.3.3.pkg
│   ├── R-3.6.2.pkg
│   ├── RStudio-1.2.5033.dmg
│   └── WorkingDir
│       └── data
├── DataHarvestingWin
│   ├── C-path Start links
│   │   ├── QGIS 3.10 Start Menu links
│   │   └── R and R Studio Start Menu links
│   ├── D-path Start links
│   │   ├── QGIS 3.10 Start Menu links
│   │   └── R and R Studio Start Menu links
│   ├── ProgramFiles
│   │   ├── QGIS 3.10
│   │   ├── R
│   │   └── RStudio
│   ├── StandaloneInstallers
│   │   ├── QGIS-OSGeo4W-3.10.2-2-Setup-x86_64.exe
│   │   ├── R-3.6.2-win.exe
│   │   └── RStudio-1.2.5033.exe
│   └── WorkingDir
│       └── data
├── README.txt

RStudio and Multiple R Installs

Some learners may have previous R installations. On Mac, if a new install is performed, the learner’s system will create a symbolic link, pointing to the new install as ‘Current.’ Sometimes this process does not occur, and, even though a new R is installed and can be accessed via the R console, RStudio does not find it. The net result of this is that the learner’s RStudio will be running an older R install. This will cause package installations to fail. This can be fixed at the terminal. First, check for the appropriate R installation in the library;

ls -l /Library/Frameworks/R.framework/Versions/

We are currently using R 3.x.y If it isn’t there, they will need to install it. If it is present, you will need to set the symbolic link to Current to point to the 3.x.y directory:

ln -s /Library/Frameworks/R.framework/Versions/3.x.y /Library/Frameworks/R.framework/Version/Current

Then restart RStudio.

Technical Tips and Tricks

Other Resources

If you encounter a problem during a workshop, feel free to contact the maintainers by email or open an issue.

For a more in-depth coverage of topics of the workshops, you may want to read “R for Data Science” by Hadley Wickham and Garrett Grolemund.