GForest Help on FIA/Google Maps

Use the "submitG" button to create a map showing the distribution of FIA plots on top of a Google Maps background. Your data and variable selections determine what is shown on the map. The result is returned as a pdf file. Select a qualitative variable and a quantitative variable (y) for display. The y-variable is divided into 4 groups for display purposes. Each group is chosen so that it contains 25% of the FIA plots (histogram equalization).

Customize the default map appearance

  • type: the Google map type that forms the background map. Select "state" to get a darkened background with white state boundaries.
  • color: the color scheme used to display the FIA data
  • zoom: zoom in or zoom out relative to the default zoom
  • plot: the default is a bubble plot. Standard uses shapes instead of size to display the quantitative variable. Standard-reverse uses colors for the quantitative variable. "qualVar only" will only use the qualitative variable for the mapping (good for large extent maps).
  • smooth: Default is no, yes means that loess smoothing will be applied. This will make the data seem much more orderly and might reveal regional patterns.
  • legend: 'default' puts the legend in the upper right corner of the map, but it might cover some of the map; 'none' eliminates the legend entirely; 'top', 'bottom' and 'right' keeps the legend off the map into those respective locations, but the map ends up being smaller.

To get back to the default configuration, simply click on the left-most radio buttons.


  1. Alabama, Georgia and Florida: no smoothing, bubble plot, state background, default zoom, rainbow colors pdf (978KB)
  2. same as above, but with loess smooting/interpolation. pdf (987KB)
  3. same as above but showing owner groups, "heat" color option, and "hybrid" Google map type option pdf (1.5MB)
  4. "reverse points map" where colors indicate levels of quantitative variable and point shapes indicate the categorical variable levels. This uses "gforest" colors, state background and loess smoothing pdf (723KB)

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