Mapping Toolbox | ![]() ![]() |
Display small circle defined via mouse clicks
Syntax
h = scircleg(ncirc) h = scircleg(ncirc,npts) h = scircleg(ncirc,linestyle
) h = scircleg(ncirc,npts,linestyle
) h = scircleg(ncirc,PropertyName
,PropertyValue,...) h = scircleg(ncirc,npts,PropertyName
,PropertyValue,...) [lat,lon] = scircleg(ncirc,npts,PropertyName
,PropertyValue,...) h = scircleg(track
,ncirc,...)
Background
A small circle is the locus of all points an equal surface distance from a given center. For true small circles, this distance is always calculated in a great circle sense; however, the scircleg
command allows a locus to be calculated using distances in a rhumb line sense as well. You can modify the circle after creation by shift-clicking on it. The circle is then in a edit mode, during which you can change the size and position by dragging control points, or by entering values into a control panel. Shift-clicking again exits the edit mode.
Description
This function is used to define small circles for display using mouse clicks. For each circle, two clicks are required: one to mark the center of the circle and one to mark any point on the circle itself, thereby defining the radius.
h = scircleg(ncirc) brings forward the current map axes and waits for the user to make (2 x
ncirc
) mouse clicks. The output h
is a vector of handles for the ncirc
small circles, which are then displayed.
h = scircleg(ncirc,npts) specifies the number of plotting points to be used for each small circle. npts
is 100 by default.
h = scircleg(ncirc,linestyle
) specifies the line style for the displayed small circles, where linestyle
is any line style string recognized by the standard MATLAB function line
.
h = scircleg(ncirc,PropertyName
,PropertyValue,...) allows property/value pairs to be set, where PropertyName
and PropertyValue
are recognized by the line
command.
[lat,lon] = scircleg(ncirc,npts,...) returns the coordinates of the plotted points rather than the handles of the small circles. Successive circles are stored in separate columns of lat
and lon
.
h = scircleg(track,ncirc,...) specifies the logic with which ranges are calculated. If the string track is 'gc'
(the default), great circle distance is used. It track is 'rh'
, rhumb line distance is used.
See Also
scircle1 |
Small circle from center, azimuth, and radius |
scircle2 |
Small circle from center and perimeter point |
![]() | scircle2 | scxsc | ![]() |