Plot Geographic Data on a Map in MATLAB

Geographic displays provide insight into data with latitude and longitude components. Though you could display your geographic data in MATLAB as a plot of x and y, it will look distorted and won’t contain any contextual information such as political boundaries, roads, and other geographic features.

In MATLAB, geographic base maps can provide this background context when plotting your geographic data. These are tiled, multi-resolution web maps that allow you to pan and zoom on different regions of your plot, automatically loading new base map imagery as you do so.

MATLAB makes it easy to plot data on top of a geographic base map inside a MATLAB figure. There are two types of geographic maps you can make in a MATLAB figure. The simplest is a plot in a geographic axes, which behaves much like a regular MATLAB axes. Use plotting functions along with the hold on command to mix points, lines, text, and density plots in one geoaxes. Here’s an example of this type of plotting. We’ll first use geodensityplot, geoplot, and geoscatter to visualize our density, line, and point data respectively. Then we can customize the view of the data, changing the basemap and the limits, and annotating the plot with text, a legend, and a title.

The second type of geographic map in MATLAB is a geographic bubble chart, which can indicate a continuous variable by bubble size and a categorical variable by bubble color. This is a specialized chart type providing both bubble and categorical legends. 

MATLAB’s base maps for global and regional scales are loaded from the web by default, but the data can also be downloaded from MATLAB Add-Ons to be used without an internet connection. Web maps with street-level data, topography, or other specialized base layer representations can be loaded from third-party sources. You can easily add web maps from a range of third-party sources using the addCustomBasemap function, available in Mapping Toolbox.

These functions for overlaying latitude and longitude data on web map base layers are available in MATLAB. If you need to go further, Mapping Toolbox provides additional functions for visualizing data in other projected coordinate systems, converting between systems, and performing geodesy calculations such as calculating distances and areas. Mapping Toolbox also allows you to read and write data between different types of standard geographic file types such as shapefiles, GPX files, and GeoTIFF files.