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comparison scripts/general/pol2cart.m @ 10688:7357e37f34fa

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coordinate transforms: add option to operate on column matrix of coordinates.
author Rik <octave@nomad.inbox5.com>
date Tue, 08 Jun 2010 21:47:05 -0700
parents 742cf6388a8f
children be55736a0783
comparison
equal deleted inserted replaced
10687:a8ce6bdecce5 10688:7357e37f34fa
15 ## You should have received a copy of the GNU General Public License 15 ## You should have received a copy of the GNU General Public License
16 ## along with Octave; see the file COPYING. If not, see 16 ## along with Octave; see the file COPYING. If not, see
17 ## <http://www.gnu.org/licenses/>. 17 ## <http://www.gnu.org/licenses/>.
18 18
19 ## -*- texinfo -*- 19 ## -*- texinfo -*-
20 ## @deftypefn {Function File} {[@var{x}, @var{y}] =} pol2cart (@var{theta}, @var{r}) 20 ## @deftypefn {Function File} {[@var{x}, @var{y}] =} pol2cart (@var{theta}, @var{r})
21 ## @deftypefnx {Function File} {[@var{x}, @var{y}, @var{z}] =} pol2cart (@var{theta}, @var{r}, @var{z}) 21 ## @deftypefnx {Function File} {[@var{x}, @var{y}, @var{z}] =} pol2cart (@var{theta}, @var{r}, @var{z})
22 ## @deftypefnx {Function File} {[@var{x}, @var{y}] =} pol2cart (@var{p})
23 ## @deftypefnx {Function File} {[@var{x}, @var{y}, @var{z}] =} pol2cart (@var{p})
24 ## @deftypefnx {Function File} {@var{C} =} pol2cart (@dots{})
22 ## Transform polar or cylindrical to Cartesian coordinates. 25 ## Transform polar or cylindrical to Cartesian coordinates.
23 ## @var{theta}, @var{r} (and @var{z}) must be the same shape, or scalar. 26 ##
27 ## @var{theta}, @var{r}, (and @var{z}) must be the same shape, or scalar.
24 ## @var{theta} describes the angle relative to the positive x-axis. 28 ## @var{theta} describes the angle relative to the positive x-axis.
25 ## @var{r} is the distance to the z-axis (0, 0, z). 29 ## @var{r} is the distance to the z-axis (0, 0, z).
26 ## @seealso{cart2pol, cart2sph, sph2cart} 30 ## If called with a single matrix argument then each row of @var{p}
31 ## represents the polar/(cylindrical) coordinate (@var{x}, @var{y} (, @var{z})).
32 ##
33 ## If only a single return argument is requested then return a matrix
34 ## @var{C} where each row represents one Cartesian coordinate
35 ## (@var{x}, @var{y} (, @var{z})).
36 ## @seealso{cart2pol, sph2cart, cart2sph}
27 ## @end deftypefn 37 ## @end deftypefn
28 38
29 ## Author: Kai Habel <kai.habel@gmx.de> 39 ## Author: Kai Habel <kai.habel@gmx.de>
30 ## Adapted-by: jwe 40 ## Adapted-by: jwe
31 41
32 function [x, y, z] = pol2cart (theta, r, z) 42 function [x, y, z] = pol2cart (theta, r, z)
33 43
34 if (nargin < 2 || nargin > 3) 44 if (nargin < 1 || nargin > 3)
35 error ("pol2cart: number of arguments must be 2 or 3"); 45 print_usage ();
36 endif 46 endif
37 47
38 if (nargin == 2 && nargout > 2) 48 if (nargin == 1)
39 error ("pol2cart: number of output arguments must not be greater than number of input arguments"); 49 if (ismatrix (theta) && (columns (theta) == 2 || columns (theta) == 3))
50 if (columns (theta) == 3)
51 z = theta(:,3);
52 else
53 z = [];
54 endif
55 r = theta(:,2);
56 theta = theta(:,1);
57 else
58 error ("pol2car: matrix input must have 2 or 3 columns [THETA, R (, Z)]");
59 endif
60 elseif (nargin == 2)
61 if (! ((ismatrix (theta) && ismatrix (r))
62 && (size_equal (theta, r) || isscalar (theta) || isscalar (r))))
63 error ("pol2cart: arguments must be matrices of same size, or scalar");
64 endif
65 elseif (nargin == 3)
66 if (! ((ismatrix (theta) && ismatrix (r) && ismatrix (z))
67 && (size_equal (theta, r) || isscalar (theta) || isscalar (r))
68 && (size_equal (theta, z) || isscalar (theta) || isscalar (z))
69 && (size_equal (r, z) || isscalar (r) || isscalar (z))))
70 error ("pol2cart: arguments must be matrices of same size, or scalar");
71 endif
40 endif 72 endif
41 73
42 if ((ismatrix (theta) && ismatrix (r) && (nargin == 2 || ismatrix (z))) 74 x = r .* cos (theta);
43 && (size_equal (theta, r) || isscalar (theta) || isscalar (r)) 75 y = r .* sin (theta);
44 && (nargin == 2 || size_equal (theta, z) || isscalar (theta) || isscalar (z))
45 && (nargin == 2 || size_equal (r, z) || isscalar (r) || isscalar (z)))
46 76
47 x = cos (theta) .* r; 77 if (nargout <= 1)
48 y = sin (theta) .* r; 78 x = [x, y, z];
49
50 else
51 error ("pol2cart: arguments must be matrices of same size, or scalar");
52 endif 79 endif
53 80
54 endfunction 81 endfunction
55 82
56 %!test 83 %!test
101 %! [x, y, z2] = pol2cart (t, r, z); 128 %! [x, y, z2] = pol2cart (t, r, z);
102 %! assert (x, [1, 2, 3], eps); 129 %! assert (x, [1, 2, 3], eps);
103 %! assert (y, [0, 0, 0] / sqrt(2), eps); 130 %! assert (y, [0, 0, 0] / sqrt(2), eps);
104 %! assert (z, z2); 131 %! assert (z, z2);
105 132
133 %!test
134 %! P = [0, 0; pi/4, sqrt(2); pi/4, 2*sqrt(2)];
135 %! C = [0, 0; 1, 1; 2, 2];
136 %! assert (pol2cart(P), C, sqrt(eps));
137
138 %!test
139 %! P = [0, 0, 0; pi/4, sqrt(2), 1; pi/4, 2*sqrt(2), 2];
140 %! C = [0, 0, 0; 1, 1, 1; 2, 2, 2];
141 %! assert (pol2cart(P), C, sqrt(eps));
142