Mercurial > hg > octave-nkf
diff scripts/general/sph2cart.m @ 8533:fb1b87ea4af9
Permit scalars when transforming coordinates.
author | Ben Abbott <bpabbott@mac.com> |
---|---|
date | Sat, 17 Jan 2009 17:32:11 -0500 |
parents | a1dbe9d80eee |
children | eb63fbe60fab |
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--- a/scripts/general/sph2cart.m +++ b/scripts/general/sph2cart.m @@ -19,7 +19,7 @@ ## -*- texinfo -*- ## @deftypefn {Function File} {[@var{x}, @var{y}, @var{z}] =} sph2cart (@var{theta}, @var{phi}, @var{r}) ## Transform spherical to cartesian coordinates. -## @var{x}, @var{y} and @var{z} must be of same shape. +## @var{x}, @var{y} and @var{z} must be of same shape, or scalar. ## @var{theta} describes the angle relative to the x-axis. ## @var{phi} is the angle relative to the xy-plane. ## @var{r} is the distance to the origin (0, 0, 0). @@ -29,20 +29,60 @@ ## Author: Kai Habel <kai.habel@gmx.de> ## Adapted-by: jwe -function [X, Y, Z] = sph2cart (Theta, Phi, R) +function [x, y, z] = sph2cart (theta, phi, r) if (nargin != 3) print_usage (); endif - if ((! (ismatrix (Theta) && ismatrix (Phi) && ismatrix (R))) - || (! size_equal (Theta, Phi)) - || (! size_equal (Theta, R))) - error ("sph2cart: arguments must be matrices of same size"); + if ((ismatrix (theta) && ismatrix (phi) && ismatrix (r)) + && (size_equal (theta, phi) || isscalar (theta) || isscalar (phi)) + && (size_equal (theta, r) || isscalar (theta) || isscalar (r)) + && (size_equal (phi, r) || isscalar (phi) || isscalar (r))) + + x = r .* cos (phi) .* cos (theta); + y = r .* cos (phi) .* sin (theta); + z = r .* sin (phi); + + else + error ("sph2cart: arguments must be matrices of same size, or scalar"); endif - X = R .* cos (Phi) .* cos (Theta); - Y = R .* cos (Phi) .* sin (Theta); - Z = R .* sin (Phi); +endfunction + +%!test +%! t = [0, 0, 0]; +%! p = [0, 0, 0]; +%! r = [0, 1, 2]; +%! [x, y, z] = sph2cart (t, p, r); +%! assert (x, r); +%! assert (y, [0, 0, 0]); +%! assert (z, [0, 0, 0]); -endfunction +%!test +%! t = 0; +%! p = [0, 0, 0]; +%! r = [0, 1, 2]; +%! [x, y, z] = sph2cart (t, p, r); +%! assert (x, r); +%! assert (y, [0, 0, 0]); +%! assert (z, [0, 0, 0]); + +%!test +%! t = [0, 0, 0]; +%! p = 0; +%! r = [0, 1, 2]; +%! [x, y, z] = sph2cart (t, p, r); +%! assert (x, r); +%! assert (y, [0, 0, 0]); +%! assert (z, [0, 0, 0]); + +%!test +%! t = [0, 0.5, 1]*pi; +%! p = [0, 0, 0]; +%! r = 1; +%! [x, y, z] = sph2cart (t, p, r); +%! assert (x, [1, 0, -1], eps); +%! assert (y, [0, 1, 0], eps); +%! assert (z, [0, 0, 0], eps); +