Re: help with gnuplot

[John Eaton]

address@hidden (Shu-Kit Yeung) wrote:

: I am seeking help for using octave to make "movies" for sequence of
: plots like MATLAB can. I will be thankful if any one can give the
: information. Thank you for your attention!!

The following example should sort of work, at least on an X display
and a fast machine.  It doesn't actually generate a movie (like an
MPEG file), it just displays a series of plots.  (I would certainly
welcome changes for generating MPEG files if someone wants to do the
work.)

Thanks,

jwe

-------------------------------hat_movie.m-------------------------------
function hat_movie (nlines, nframes)

# usage: hat_movie (nlines, nframes)
#
# Draw a series of `sombreros' in three dimensions using `nlines' grid
# lines.  The function plotted is
#
#   z = k * sin (x^2 + y^2) / (x^2 + y^2);
#
# where k varies between 0 and 1.

  if (nargin == 0)
    nlines = 31;
    nframes = 7;
  elseif (nargin == 1)
    nframes = 7;
  elseif (nargin > 2)
    error ("usage: hat_movie (nlines, nframes)");
  endif

  set zrange [-0.6:1.1]

  for i = 1:nframes

    if (nframes > 1)
      k = (i-1)/(nframes-1);
    else
      k = 1;
    endif

    x = y = linspace (-8, 8, nlines)';
    [xx, yy] = meshdom (x, y);
    r = sqrt (xx .^ 2 + yy .^ 2) + eps;
    z = k * sin (r) ./ r;

    mesh (x, y, z);

  endfor

endfunction