Mercurial > hg > octave-nkf
changeset 17120:a639221f9863
sombrero.m: Overhaul documentation and make calling forms equivalent to peaks()
* scripts/plot/sombrero.m: Overhaul documentation. Return only Z argument if
nargout == 1.
* scripts/plot/ribbon.m, scripts/plot/surf.m, scripts/plot/surfc.m: Rephrase
%!tests to take advantage of new calling form for sombrero.
| author | Rik <rik@octave.org> |
|---|---|
| date | Wed, 31 Jul 2013 13:43:44 -0700 |
| parents | bd50e0660545 |
| children | d4549655b92e |
| files | scripts/plot/ribbon.m scripts/plot/sombrero.m scripts/plot/surf.m scripts/plot/surfc.m |
| diffstat | 4 files changed, 27 insertions(+), 8 deletions(-) [+] |
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--- a/scripts/plot/ribbon.m +++ b/scripts/plot/ribbon.m @@ -113,7 +113,7 @@ %! clf; %! colormap ('default'); %! [x, y, z] = sombrero (); -%! [x, y] = meshgrid (x, y); +%! [~, y] = meshgrid (x, y); %! ribbon (y, z); %!FIXME: Could have some input validation tests here
--- a/scripts/plot/sombrero.m +++ b/scripts/plot/sombrero.m @@ -19,15 +19,32 @@ ## -*- texinfo -*- ## @deftypefn {Function File} {} sombrero () ## @deftypefnx {Function File} {} sombrero (@var{n}) -## Produce the familiar three-dimensional sombrero plot using @var{n} -## grid lines. If @var{n} is omitted, a value of 41 is assumed. +## @deftypefnx {Function File} {@var{z} =} sombrero (@dots{}) +## @deftypefnx {Function File} {[@var{x}, @var{y}, @var{z}] =} sombrero (@dots{}) +## Plot the familiar 3-D sombrero function. ## ## The function plotted is +## @tex +## $$z = { \rm{sin} (\sqrt {(x^2 + y^2)}) \over \sqrt {(x^2 + y^2)} }$$ +## @end tex +## @ifnottex ## ## @example ## z = sin (sqrt (x^2 + y^2)) / (sqrt (x^2 + y^2)) ## @end example -## @seealso{surf, meshgrid, mesh} +## +## @end ifnottex +## Called without a return argument, @code{sombrero} plots the surface of the +## above function over the meshgrid [-8,8] using @code{surf}. +## +## If @var{n} is a scalar the plot is made with @var{n} grid lines. +## The default value for @var{n} is 41. +## +## 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{peaks, meshgrid, mesh, surf} ## @end deftypefn ## Author: jwe @@ -43,11 +60,13 @@ tx = linspace (-8, 8, n)'; ty = tx; [xx, yy] = meshgrid (tx, ty); - r = sqrt (xx .^ 2 + yy .^ 2) + eps; + r = sqrt (xx .^ 2 + yy .^ 2) + eps; # eps prevents div/0 errors tz = sin (r) ./ r; + if (nargout == 0) surf (tx, ty, tz); - box ("off"); + elseif (nargout == 1) + z = tz; else x = tx; y = ty;