track2

Geographic track points from starting and ending points

Syntax

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2)

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,units)

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,ellipsoid)

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,ellipsoid,units)

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,ellipsoid,units,npts)

[lattrk,lontrk] = track2(method,___)

mat = track2(___)

Description

Track Points Along Unit Sphere

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2) finds the latitude and longitude coordinates of points along a great circle track from the starting point with coordinates lat1 and lon1 to the ending point with coordinates lat2 and lon2. This syntax references the coordinates to a unit sphere and assumes that all input arguments are in degrees.

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,units) specifies the angle units units for the inputs and outputs.

Track Points Along Ellipsoid

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,ellipsoid) finds track points along a geodesic on the reference ellipsoid ellipsoid.

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,ellipsoid,units) specifies both the reference ellipsoid and the units for the coordinates.

[lattrk,lontrk] = track2(lat1,lon1,lat2,lon2,ellipsoid,units,npts) specifies the number of track points to find.

Additional Options

[lattrk,lontrk] = track2(method,___), where method is "rh", calculates track points along rhumb lines. The default for method is "gc", which calculates track points along great circles (for spheres) or geodesics (for ellipsoids).

mat = track2(___) returns the latitude and longitude coordinates of the track points in the matrix mat.

Examples

Find Track Points Between Starting and Ending Points

Find points along a great circle track from New York City to Paris.

[latgc,longc] = track2(40.71,-74.01,48.86,2.35);

Find points along a rhumb line track between the same cities.

[latrh,lonrh] = track2("rh",40.71,-74.01,48.86,2.35);

Compare the great circle and rhumb line tracks by displaying the track points on a map. Use a blue line for the great circle track and a red line for the rhumb line track.

geoplot(latgc,longc,"b")
hold on
geoplot(latrh,lonrh,"r")

Find Track Points Along Ellipsoid

Create a World Geodetic System of 1984 (WGS84) reference ellipsoid with a length unit of nautical miles.

wgs84 = wgs84Ellipsoid("nm");

Find points along a geodesic track from New York City to Paris.

[lattrk,lontrk] = track2(40.71,-74.01,48.86,2.35,wgs84);

Display the track on a map.

geoplot(lattrk,lontrk)

Input Arguments

lat1 — Latitude of starting point

scalar | column vector

Latitude of the starting point, specified as a scalar or column vector.

The sizes of lat1 and lon1 must match.

To find multiple tracks from a single starting point, specify lat1 and lon1 as scalars and lat2 and lon2 as column vectors.

Data Types: single | double

lon1 — Longitude of starting point

scalar | column vector

Longitude of the starting point, specified as a scalar or column vector.

The sizes of lat1 and lon1 must match.

To find multiple tracks from a single starting point, specify lat1 and lon1 as scalars and lat2 and lon2 as column vectors.

Data Types: single | double

lat2 — Latitude of ending point

scalar | column vector

Latitude of the ending point, specified as a scalar or column vector.

The sizes of lat2 and lon2 must match.

To find multiple tracks from a single starting point, specify lat1 and lon1 as scalars and lat2 and lon2 as column vectors.

Data Types: single | double

lon2 — Longitude of ending point

scalar | column vector

Longitude of the ending point, specified as a scalar or column vector.

The sizes of lat2 and lon2 must match.

To find multiple tracks from a single starting point, specify lat1 and lon1 as scalars and lat2 and lon2 as column vectors.

Data Types: single | double

units — Angle unit

"degrees" (default) | "radians"

Angle unit, specified as one of these options:

• "degrees" — Degrees

• "radians" — Radians

Data Types: char | string

ellipsoid — Reference ellipsoid

[1 0] (default) | referenceSphere object | referenceEllipsoid object | oblateSpheroid object | two-element numeric vector

Reference ellipsoid, specified as a referenceSphere object, a referenceEllipsoid object, an oblateSpheroid object, or a two-element vector of the form [semimajor_axis eccentricity], where semimajor_axis is the length of the semimajor axis and eccentricity is the eccentricity. The values semimajor_axis and eccentricity must be of data type double.

The default value of [1 0] represents the unit sphere.

method — Track method

"gc" (default) | "rh"

Track method, specified as one of these options:

• "gc" — Find track points along a great circle path (for spheres) or a geodesic path (for ellipsoids).

• "rh" — Find track points along a rhumb line path.

For more information about rhumb lines and great circles, see Comparison of Rhumb Lines and Great Circles.

Data Types: char | string

npts — Number of track points

100 (default) | positive integer

Number of track points to include in lattrk and lontrk, specified as a positive integer.

Data Types: double

Output Arguments

lattrk — Latitude coordinates of track points

column vector | matrix

Latitude coordinates of the track points, returned as a column vector with npts elements or a matrix of size npts-by-length(lat2). The function returns lattrk as a column vector if lat2 and lon2 are scalars, and as a matrix if lat2 and lon2 are column vectors.

lontrk — Longitude coordinates of track points

column vector | matrix

Longitude coordinates of the track points, returned as a column vector with npts elements or a matrix of size npts-by-length(lon2). The function returns lattrk as a column vector if lat2 and lon2 are scalars, and as a matrix if lat2 and lon2 are column vectors.

mat — Latitude and longitude coordinates of track points

matrix

Latitude and longitude coordinates of the track points, returned as a matrix equivalent to [lattrk lontrk].

Version History

Introduced before R2006a