# Documentation of m_range_ring

Global Index (all files) (short | long) | Local Index (files in subdir) (short | long)

## Function Synopsis

    h=m_range_ring(long,lat,range,varargin);

## Help text

     M_RANGE_RING Creates range rings on a map
        M_RANGE_RING(LONG,LAT,RANGE) creates a range ring of range RANGE
        km centered at the position specified by LONG and LAT. Range rings
        will generally appear as small (almost) circles for short ranges,
        but will be distorted at longer ranges.

        If RANGE is a vector, concentric rings at the specified ranges
        are drawn. If LONG,LAT are vectors, rings are drawn around
        all specified locations.

        The appearance of lines can be modified using the usual
        line properties thus:
        M_RANGE_RING(LONG,LAT,RANGE, <line property/value pairs>)

        Sometimes you may need to adjust the number of points plotted
        in each range ring (this can happen if the ring is at the extreme
        edge of certian projections). THis can be done using
        M_RANGE_RING(LONG,LAT,RANGE,NPTS, <line property/value pairs>)

        NB: Earth radius is assumed to 6378.137km (WGS-84 value), and
        calculations are for spherical geometry.

## Cross-Reference Information

This function calls | This function is called by
--- | ---
m_ll2xy | m_demo

Pierre-Michel THEVENY <theveny@dt.insu.cnrs.fr>