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Mapping Quantitative Data: Colorization, Resizing, & Frequency Counts
Contents
This tutorial will teach you how to use GPS Visualizer's "data" form to create maps of quantitative data. Until this document has been completed, please feel free to contact me with any questions you might have about the topics listed below.
1: Colorizing and resizing waypoints based on your data
GPS Visualizer's map input form for quantitive data contains some options not found in the other map forms: notably, the ability to resize and colorize points based on any field in your data. For illustrative purposes, let's use the sample data from the Waypoints Tutorial, but we'll add another plottable field to our volcano data: age of last eruption. And, for the sake of keeping it simple, let's remove the description.
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To get a map like this, specify "altitude/elevation" for "Colorize points by..." on the data form. We haven't done anything with the "age of last eruption" field yet.
(If you're thinking, "but wait, we removed the description field, why are there descriptions under the names of the points?" -- you're very observant. It turns out GPS Visualizer will build a description field for you, based on the field that was used to colorize the waypoints.)
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To get this map, leave the "Colorize points" setting on "altitude/elevation," but change the "Resize" setting to "custom field" and enter "age of last eruption" in the "Custom resizing field" box that appears.
Now we're mapping in four dimensions: latitude & longitude (shown by the position on the map), altitude (red is the lowest altitude, purple is the highest), and age of last eruption (smaller circles indicate smaller ages). By the way, if you think it would make more sense to have volcanoes with more recent eruptive activity get larger circles, you could use negative numbers for the ages.
(This time, a description was automatically constructed out of the resizing field. If you don't like how GPS Visualizer creates default descriptions, make sure you specify your own preferred descriptions in the input data.)
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2: Creating custom icons in Google Earth
Coming soon.
3: Automatic frequency counts using ZIP codes, states, or countries
Coming soon.
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