track2

Geographic track points from starting and ending points

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    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.

    example

    [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.

    example

    [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).

    example

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

    Examples

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    Open Live Script

    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")

    Open Live Script

    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

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    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

    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

    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

    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

    Angle unit, specified as one of these options:

    • "degrees" — Degrees

    • "radians" — Radians

    Data Types: char | string

    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.

    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

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

    Data Types: double

    Output Arguments

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    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.

    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.

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

    Version History

    Introduced before R2006a

    See Also

    Functions

    Topics