scircle2
Small circles from center and perimeter
Syntax
[lat,lon] = scircle2(lat1,lon1,lat2,lon2)
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,ellipsoid)
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,units)
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,ellipsoid,units)
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,ellipsoid,units,npts)
[lat,lon] = scircle2(track,...)
mat = scircle2(...)
mat = [lat lon]
Description
[lat,lon] = scircle2(lat1,lon1,lat2,lon2) computes
small circles (on a sphere) with centers at the points lat1,lon1 and
points on the circles at lat2,lon2. The inputs
can be scalar or column vectors.
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,ellipsoid)
computes the small circle on the ellipsoid defined by the input
ellipsoid, rather than by assuming a sphere.
ellipsoid is a referenceSphere, referenceEllipsoid, or oblateSpheroid object, or a vector of the form [semimajor_axis
eccentricity]. Default is a unit sphere.
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,units) and
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,ellipsoid,units)
are valid calling forms, which use the input units to define the
angle units of the inputs and outputs. If you omit units,
'degrees' is assumed.
[lat,lon] = scircle2(lat1,lon1,lat2,lon2,ellipsoid,units,npts) uses the
scalar input npts to determine the number of points per track
computed. The default value of npts is 100.
[lat,lon] = scircle2(track,...) uses track to define either a great
circle or a rhumb line radius. If track' = 'gc', then small circles
are computed. If track = 'rh', then circles with radii of constant
rhumb line distance are computed. If you omit track, 'gc' is
assumed.
mat = scircle2(...) returns a single output
argument where mat = [lat lon]. This is useful
if a single circle is computed.
Multiple circles can be defined from a single center point by
providing scalar lat1,lon1 inputs and column vectors
for the points on the circumference, lat2,lon2.
Examples
Plot Locus of Points Equidistant from New Delhi
Plot the locus of all points the same distance from New Delhi as Kathmandu.
axesm('mercator','MapLatlimit',[0 40],'MapLonLimit',[60 110]); load coastlines % For reference plotm(coastlat,coastlon,'k'); % New Delhi lat1 = 29; lon1 = 77.5; % Kathmandu lat2 = 27.6; lon2 = 85.5; % Plot the cities plotm([lat1 lat2],[lon1 lon2],'b*') [latc,lonc] = scircle2(lat1,lon1,lat2,lon2); plotm(latc,lonc,'b')
