Matlab-like view() function

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

Matlab-like view() function

Peter Hopfgartner-5
Hi,

I've attached the the m-filr that implements and a modified (from 2.1.5)
mesh.m file where the gnuplot gsets have been substituted with view();

It implements a subset of the MatLab view function, but it was just that
what I needed.

For JWE: I started looking into gtk-- to see if we could get a nice GUI
for the plotting, but I'm very slow since I'm a lot at work these days,
sorry.

Suggestion: should we take the spline function that comes with
plotutils?

Question: Have you had a look at gsl-0.3a.tar.gz on alpha.gnu.org, seems
to be a junior Octave-lib!

Regards,

                                        Peter

## Copyright (C) 1996, 1997 John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
## 02111-1307, USA.

## usage: mesh (x, y, z)
##
## Surface plot.  If x, y, and z are matrices with the same dimensions,
## then corresponding elements represent vertices of the plot.  If x and
## y are vectors, then a typical vertex is (x(j), y(i), z(i,j)).  Thus,
## columns of z correspond to different x values and rows of z correspond
## to different y values.
##
## See also: plot, semilogx, semilogy, loglog, polar, meshgrid, meshdom,
##           contour, bar, stairs, gplot, gsplot, replot, xlabel, ylabel, title

## Author: jwe

function mesh (x, y, z)

  ## XXX FIXME XXX -- the plot states should really just be set
  ## temporarily, probably inside an unwind_protect block, but there is
  ## no way to determine their current values.

  if (nargin == 1)
    z = x;
    if (is_matrix (z))
      gset hidden3d;
      gset data style lines;
      gset surface;
      gset nocontour;
      gset noparametric;
      view();
      gsplot (z');
    else
      error ("mesh: argument must be a matrix");
    endif
  elseif (nargin == 3)
    if (is_vector (x) && is_vector (y) && is_matrix (z))
      xlen = length (x);
      ylen = length (y);
      if (xlen == columns (z) && ylen == rows (z))
        if (rows (y) == 1)
          y = y';
        endif
        len = 3 * xlen;
        zz = zeros (ylen, len);
        k = 1;
        for i = 1:3:len
          zz(:,i)   = x(k) * ones (ylen, 1);
          zz(:,i+1) = y;
          zz(:,i+2) = z(:,k);
          k++;
        endfor
        gset hidden3d;
        gset data style lines;
        gset surface;
        gset nocontour;
        gset parametric;
        view();
        gsplot (zz);
        gset noparametric;
      else
        msg = "mesh: rows (z) must be the same as length (x) and";
        msg = sprintf ("%s\ncolumns (z) must be the same as length (y)", msg);
        error (msg);
      endif
    elseif (is_matrix (x) && is_matrix (y) && is_matrix (z))
      xlen = columns (z);
      ylen = rows (z);
      if (xlen == columns (x) && xlen == columns (y) &&
        ylen == rows (x) && ylen == rows(y))
        len = 3 * xlen;
        zz = zeros (ylen, len);
        k = 1;
        for i = 1:3:len
          zz(:,i)   = x(:,k);
          zz(:,i+1) = y(:,k);
          zz(:,i+2) = z(:,k);
          k++;
        endfor
        gset hidden3d;
        gset data style lines;
        gset surface;
        gset nocontour;
        gset parametric;
        view();
        gsplot (zz);
        gset noparametric;
      else
        error ("mesh: x, y, and z must have same dimensions");
      endif
    else
      error ("mesh: x and y must be vectors and z must be a matrix");
    endif
  else
    usage ("mesh (z)");
  endif

endfunction

## Copyright (C) 1996 John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
## 02111-1307, USA.

## usage: view(azimuth, elevation)
##
## Sets the viewpoint for a 3D surface plot.
##
## view([azimuth, elevation]) same as above
##
## [ret_az, ret_el] = view() sends the actual viewpoint to
## gnuplot and places it in [ret_az, ret_el].
##
## view(2) sets the viewpoint along the x axis
## view(3) sets the azimuth = 360 - 37.5 and elevation = 30
##
## NOTE:  Doesn't implement the full functionality of the Matlab
## equivalent yet.
##
## Input:
##   azimuth   : Rotation around z-axis
##   elevation : Rotation around x-axis
##

## Author: Peter Hopfgartner ([hidden email])

function [ret_az, ret_el] = view (azimuth, elevation)

  ## global variables to keep track of view options

  global __view_azimuth__ = - 37.5 + 360;
  global __view_elevation__ = 30;

  if (nargin == 0)

  elseif (nargin == 1 && azimuth == 2)
    __view_azimuth__ = 0;
    __view_elevation__ = 90;
  elseif (nargin == 1 && azimuth == 3)
    __view_azimuth__ = -37.5 + 360;
    __view_elevation__ = 30;
  elseif (nargin == 1 && size(azimuth) == [1,2])
    __view_azimuth__ = azimuth(1);
    __view_elevation__ = azimuth(2);    
  elseif (nargin == 2 && is_scalar(azimuth) && is_scalar(elevation))
    __view_azimuth__ = azimuth;
    __view_elevation__ = elevation;
  else
    usage ("view (azimuth, elevation) or view ([azimuth, elevation])");
  endif
  if (__view_azimuth__ < 0 || __view_azimuth__ > 360)
    error ("azimuth must be in [0, 360]");
  elseif (__view_elevation__ < 0 || __view_elevation__ > 180)
    error ("elevation must be in [0, 180]");
  endif
  eval (sprintf("gset view %4.1f, %4.1f", __view_elevation__, \
                __view_azimuth__ ));
  ret_az = __view_azimuth__;
  ret_el = __view_elevation__;
endfunction