geodensityplot

Geographic density plot

Syntax

geodensityplot(lat,lon)

geodensityplot(lat,lon,weights)

geodensityplot(___,Name,Value)

geodensityplot(gx,___)

dp = geodensityplot(___)

Description

geodensityplot(lat,lon) creates a density plot in a geographic axes from locations specified (in degrees) by the coordinate vectors lat and lon. lat and lon must be the same size.

geodensityplot(lat,lon,weights) specifies weights for the data points in weights.

geodensityplot(___,Name,Value) specifies DensityPlot properties using one or more Name,Value pair arguments.

geodensityplot(gx,___) plots in the geographic axes specified by gx instead of the current axes.gx.

dp = geodensityplot(___) returns a DensityPlot object.

Examples

Create Geographic Density Plot

Set up latitude and longitude data.

lon = linspace(-170,170,3000) + 10*rand(1,3000);
lat = 50 * cosd(3*lon) + 10*rand(size(lon));

Specify weights for each data point.

weights = 101 + 100*(sind(2*lon));

Create the geographic density plot, specifying the colors used with the plot.

geodensityplot(lat,lon,weights,'FaceColor','interp')

Input Arguments

lat — Latitude coordinates of data points

real, numeric, finite vector within the range [-90 90]

Latitude coordinates of data points, specified as a real, numeric, finite vector in degrees, within the range [-90 90]. The vector can contain embedded NaNs. lat must be the same size as lon.

Example: [43.0327 38.8921 44.0435]

Data Types: single | double

lon — Longitude coordinates in degrees

real, numeric, finite vector

Longitude coordinates in degrees, specified as a real, numeric, finite vector. The vector can contain embedded NaNs. lon must be the same size as lat.

Longitudes must span less than (or equal to) 360 degrees.

Example: [-107.5556 -77.0269 -72.5565]

Data Types: single | double

weights — Weights assigned to data

[] (default) | scalar | numeric vector

Weights assigned to data, specified as an empty array, a scalar, or a numeric array. If you specify a numeric vector, the vector must be the same length as the lat and lon vectors. The weights vector is typically additional data you have related to the location data in lat and lon.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

gx — Target geographic axes

GeographicAxes object

Target geographic axes, specified as a GeographicAxes object.^[1] You can modify the appearance and behavior of a GeographicAxes object by setting its properties. For a list of properties, see GeographicAxes Properties.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: dp = geodensityplot(lat,lon,weights,'FaceColor','g')

Note

The density plot properties listed here are frequently used properties. For a complete list, see DensityPlot Properties.

'FaceAlpha' — Face transparency

'interp' (default) | scalar in range [0,1]

Face transparency, specified as one of these values:

• Scalar in range [0,1] — Use uniform transparency across all the faces. A value of 1 is fully opaque and 0 is completely transparent. Values between 0 and 1 are semitransparent.

• 'interp' — Use interpolated transparency for each face. The transparency varies across each face by interpolating the values at the vertices. Transparency values are chosen from the parent axes alphamap.

'FaceColor' — Face color

'interp' | ColorSpec value | RGB triplet | ...

Face color, specified as one of the values in this table.

Value	Description
'interp'	Use interpolated coloring based on density values. Colors are chosen from the parent axes colormap.
RGB triplet	Three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1], for example, [0.4 0.6 0.7].
ColorSpec	MATLAB® ColorSpec (Color Specification). You can specify some common colors by name.

'Radius' — Radius of influence each point has on density calculation

numeric scalar

Radius of influence each point has on density calculation, specified as a numeric scalar. When used in a GeographicAxes, the value is measured in meters.

Output Arguments

dp — Geographic density plot

DensityPlot

Geographic density plot, returned as a DensityPlot object.

Tips

• To customize the geographic axes, modify geographic axes properties. For a list of properties, see GeographicAxes Properties.

• if you have Mapping Toolbox™, you can specify basemaps of your own choosing using the addCustomBasemap function.

• When you plot on geographic axes, the geodensityplot function assumes that coordinates are referenced to the WGS84 coordinate reference system. If you plot using coordinates that are referenced to a different coordinate reference system, then the coordinates may appear misaligned.