doc: Rewrite docstrings for most plot functions. Emphasize clarity, use common "voice", and increase density of seealso links. * doc/interpreter/plot.txi: Add @findex entries that were in xlim.m * scripts/miscellaneous/getappdata.m scripts/miscellaneous/setappdata.m, scripts/plot/allchild.m, scripts/plot/ancestor.m, scripts/plot/area.m, scripts/plot/axes.m, scripts/plot/axis.m, scripts/plot/bar.m, scripts/plot/barh.m, scripts/plot/box.m, scripts/plot/caxis.m, scripts/plot/cla.m, scripts/plot/clabel.m, scripts/plot/clf.m, scripts/plot/close.m, scripts/plot/closereq.m, scripts/plot/colorbar.m, scripts/plot/comet.m, scripts/plot/comet3.m, scripts/plot/compass.m, scripts/plot/contour.m, scripts/plot/contour3.m, scripts/plot/contourc.m, scripts/plot/contourf.m, scripts/plot/copyobj.m, scripts/plot/cylinder.m, scripts/plot/daspect.m, scripts/plot/diffuse.m, scripts/plot/ellipsoid.m, scripts/plot/errorbar.m, scripts/plot/ezcontour.m, scripts/plot/ezcontourf.m, scripts/plot/ezmesh.m, scripts/plot/ezmeshc.m, scripts/plot/ezplot.m, scripts/plot/ezplot3.m, scripts/plot/ezpolar.m, scripts/plot/ezsurf.m, scripts/plot/ezsurfc.m, scripts/plot/feather.m, scripts/plot/figure.m, scripts/plot/fill.m, scripts/plot/findall.m, scripts/plot/findobj.m, scripts/plot/fplot.m, scripts/plot/gca.m, scripts/plot/gcbf.m, scripts/plot/gcbo.m, scripts/plot/gcf.m, scripts/plot/gco.m, scripts/plot/ginput.m, scripts/plot/graphics_toolkit.m, scripts/plot/grid.m, scripts/plot/gtext.m, scripts/plot/guidata.m, scripts/plot/guihandles.m, scripts/plot/hdl2struct.m, scripts/plot/hggroup.m, scripts/plot/hidden.m, scripts/plot/hist.m, scripts/plot/hold.m, scripts/plot/ishghandle.m, scripts/plot/ishold.m, scripts/plot/isocolors.m, scripts/plot/isprop.m, scripts/plot/legend.m, scripts/plot/line.m, scripts/plot/linkprop.m, scripts/plot/loglog.m, scripts/plot/loglogerr.m, scripts/plot/mesh.m, scripts/plot/meshc.m, scripts/plot/meshgrid.m, scripts/plot/meshz.m, scripts/plot/newplot.m, scripts/plot/orient.m, scripts/plot/pareto.m, scripts/plot/patch.m, scripts/plot/pcolor.m, scripts/plot/peaks.m, scripts/plot/pie.m, scripts/plot/pie3.m, scripts/plot/plot.m, scripts/plot/plot3.m, scripts/plot/plotmatrix.m, scripts/plot/plotyy.m, scripts/plot/polar.m, scripts/plot/print.m, scripts/plot/quiver.m, scripts/plot/quiver3.m, scripts/plot/rectangle.m, scripts/plot/refresh.m, scripts/plot/refreshdata.m, scripts/plot/ribbon.m, scripts/plot/rose.m, scripts/plot/saveas.m, scripts/plot/scatter.m, scripts/plot/scatter3.m, scripts/plot/semilogx.m, scripts/plot/semilogxerr.m, scripts/plot/semilogy.m, scripts/plot/semilogyerr.m, scripts/plot/shading.m, scripts/plot/shg.m, scripts/plot/shrinkfaces.m, scripts/plot/slice.m, scripts/plot/specular.m, scripts/plot/sphere.m, scripts/plot/stairs.m, scripts/plot/stem.m, scripts/plot/stem3.m, scripts/plot/struct2hdl.m, scripts/plot/subplot.m, scripts/plot/surf.m, scripts/plot/surface.m, scripts/plot/surfc.m, scripts/plot/surfl.m, scripts/plot/tetramesh.m, scripts/plot/text.m, scripts/plot/title.m, scripts/plot/trimesh.m, scripts/plot/triplot.m, scripts/plot/trisurf.m, scripts/plot/view.m, scripts/plot/waitbar.m, scripts/plot/waitforbuttonpress.m, scripts/plot/waterfall.m, scripts/plot/whitebg.m, scripts/plot/xlabel.m, scripts/plot/xlim.m, scripts/plot/ylabel.m, scripts/plot/ylim.m, scripts/plot/zlabel.m, scripts/plot/zlim.m: Rewrite docstrings for most plot functions. Emphasize clarity, use common "voice", and increase density of seealso links.

--- a/scripts/plot/sphere.m
+++ b/scripts/plot/sphere.m
@@ -17,17 +17,33 @@
 ## <http://www.gnu.org/licenses/>.
 
 ## -*- texinfo -*-
-## @deftypefn  {Function File} {[@var{x}, @var{y}, @var{z}] =} sphere (@var{n})
-## @deftypefnx {Function File} {} sphere (@var{h}, @dots{})
-## Generate three matrices in @code{meshgrid} format, such that
-## @code{surf (@var{x}, @var{y}, @var{z})} generates a unit sphere.
-## The matrices of @code{@var{n}+1}-by-@code{@var{n}+1}.  If @var{n} is
-## omitted then a default value of 20 is assumed.
+## @deftypefn  {Function File} {} sphere ()
+## @deftypefnx {Function File} {} sphere (@var{n})
+## @deftypefnx {Function File} {} sphere (@var{hax}, @dots{})
+## @deftypefnx {Function File} {[@var{x}, @var{y}, @var{z}] =} sphere (@dots{})
+## Plot a 3-D unit sphere.
+##
+## The optional input @var{n} determines the number of faces around the
+## the circumference of the sphere.  The default value is 20.
+##
+## If the first argument @var{hax} is an axes handle, then plot into this axis,
+## rather than the current axes returned by @code{gca}.
 ##
-## Called with no return arguments, @code{sphere} call directly
-## @code{surf (@var{x}, @var{y}, @var{z})}.  If an axes handle is passed
-## as the first argument, the surface is plotted to this set of axes.
-## @seealso{peaks}
+## If outputs are requested @code{sphere} returns three matrices in
+## @code{meshgrid} format such that @code{surf (@var{x}, @var{y}, @var{z})}
+## generates a unit sphere.
+##
+## Example:
+##
+## @example
+## @group
+## [x, y, z] = sphere (40);
+## surf (3*x, 3*y, 3*z);
+## axis equal;
+## title ("sphere of radius 3");
+## @end group
+## @end example
+## @seealso{cylinder, ellipsoid, rectangle}
 ## @end deftypefn
 
 function [xx, yy, zz] = sphere (varargin)