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/peaks.m
+++ b/scripts/plot/peaks.m
@@ -22,11 +22,12 @@
 ## @deftypefnx {Function File} {} peaks (@var{x}, @var{y})
 ## @deftypefnx {Function File} {@var{z} =} peaks (@dots{})
 ## @deftypefnx {Function File} {[@var{x}, @var{y}, @var{z}] =} peaks (@dots{})
-## Generate a function with lots of local maxima and minima.  The function
-## has the form
+## Plot a function with lots of local maxima and minima.
+##
+## The function has the form
 ##
 ## @tex
-## $f(x,y) = 3 (1 - x) ^ 2 e ^ {\left(-x^2 - (y+1)^2\right)} - 10 \left({x \over 5} - x^3 - y^5)\right) - {1 \over 3} e^{\left(-(x+1)^2 - y^2\right)}$
+## $$f(x,y) = 3 (1 - x) ^ 2 e ^ {\left(-x^2 - (y+1)^2\right)} - 10 \left({x \over 5} - x^3 - y^5)\right) - {1 \over 3} e^{\left(-(x+1)^2 - y^2\right)}$$
 ## @end tex
 ## @ifnottex
 ## @verbatim
@@ -37,14 +38,21 @@
 ## @end ifnottex
 ##
 ## Called without a return argument, @code{peaks} plots the surface of the
-## above function using @code{mesh}.  If @var{n} is a scalar, the @code{peaks}
-## returns the values of the above function on a @var{n}-by-@var{n} mesh over
-## the range @code{[-3,3]}.  The default value for @var{n} is 49.
+## above function using @code{surf}.
+## 
+## If @var{n} is a scalar, @code{peaks} plots the value of the above
+## function on an @var{n}-by-@var{n} mesh over the range [-3,3].  The
+## default value for @var{n} is 49.
 ##
-## If @var{n} is a vector, then it represents the @var{x} and @var{y} values
-## of the grid on which to calculate the above function.  The @var{x} and
-## @var{y} values can be specified separately.
-## @seealso{surf, mesh, meshgrid}
+## If @var{n} is a vector, then it represents the grid values over which
+## to calculate the function.  If @var{x} and @var{y} are specified then
+## the function value is calculated over the specified grid of vertices.
+##
+## When called with output arguments, return the data for the function
+## evaluated over the meshgrid.  This can subsequently be plotted with
+## @code{surf (@var{x}, @var{y}, @var{z})}.
+## 
+## @seealso{sombrero, meshgrid, mesh, surf}
 ## @end deftypefn
 
 ## Expression for the peaks function was taken from the following paper: