MS_SPHERE - Plot a spherical plot of phasevels/anisotropy from a set of
             elastic constants.

Given an elasticity matrix and density, produce spherical figures showing
    the P- or S-wave anisotropy or the slowness surface.

MS_sphere(CC,rh,mode,...)

Usage:
    MS_sphere(CC,rh,mode)
        Mode can be 'p'(-wave), 's'(-wave), 's1' (fast s-wave) or 's2'
        (slow s-wave) for velocity plots or 'slowP','slowS1' or 'slowS2'
        for slowness plots (slowness is the inverse of velocity).

MS_sphere(CC,rh,mode,...)
     Further arguments are optional, can be combined in any order and
     change the behaviour of the function. Specific options are
     listed below.

MS_sphere(..., 'reverse')
     Unreverse the sense of the colour map. Default (no argument) is
     for blue to be fast/high as is conventional for seismic velocity
     colorscales. Setting this option results in red being fast/high.

MS_sphere(..., 'sdata',azi,inc,pol,magn)
     Overlay a S-wave (splitting) dataset onto the sphere at the points.
     indicated by the azi, inc arrays. The data are in 2 vectors: pol
     (SW orientation) and mag ( anisotropy). They are plotted as coloured
     spots with vector ticks.

MS_sphere(..., 'pdata',azi,inc,vel)
     Overlay a P-wave (velocity) dataset (in vel) onto the sphere at
     the points. indicated by the azi, inc arrays. They are plotted as
     coloured spots.

MS_sphere(..., 'FSWTickLength', length)
     Set the length of the Fast shear wave direction markers, default
     is 0.08.

MS_sphere(..., 'FSWMarkerSize', length)
     Set the size of the Fast shear wave direction markers, default
     is 4.

MS_sphere(..., 'cmap', CM)
     Redefine the colormap. CM can either be a (nx3) matrix containing a
     colormap, or a string describing a function to generate such a
     matrix (such as the built-in MATLAB colormap functions). E.g.:
     MS_sphere(C,rh,mode,'cmap','cool(64)') - uses the MATLAB
     function cool to generate a cyan-to-purple colourmap.
     The default is 'jet', reversed so blue is fast/high, as is
     conventional for seismic velocity colorscales.

MS_sphere(..., 'velmesh', levels)
     Choose the number of points used to mesh the velocity contours
     expressed in terms of the number of times the mesh spacing is
     halved. Default is 3.

MS_sphere(..., 'polmesh', levels)
     Choose the number of points used to mesh the fast shear wave
     markers. Expressed in terms of the number of times the mesh spacing is
     halved. Default is 2.

MS_sphere(..., 'dirs', array)
     Directions of interest, this should be a vector of azi,
     inc pairs, e.g., [az1 in1 az2 in2 az3 in3 az4 in4].

MS_sphere(..., 'dlen', lenght)
     Set length of doi vectors. Default is 1.5

MS_sphere(..., 'nolabels')
     Supress printing of the text labels.

MS_sphere(..., 'noaxes')
     Supress printing of the direction axes.

MS_sphere(..., 'nocbar')
     Supress printing of the colour bar.

MS_sphere(..., 'nofig')
     Suppress the figure command, so plot can be sub-plotted.

See also: MS_SPHERE, MS_PHASEVELS