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comparison scripts/plot/draw/sphere.m @ 30872:2e358088e442

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sphere.m: Add input validation of input N. * sphere.m: Check that input N is a real scalar > 0. Add BIST checks for new input validation. Rename output variables "xx,yy,zz" to "x,y,z" to match documentation. Rename internal variables "x,y,z" to "xx,yy,zz". Add %!demo.
author Rik <rik@octave.org>
date Wed, 30 Mar 2022 07:57:20 -0700
parents 796f54d4ddbf
children 597f3ee61a48
comparison
equal deleted inserted replaced
30871:1bddc0ddea74 30872:2e358088e442
51 ## @end group 51 ## @end group
52 ## @end example 52 ## @end example
53 ## @seealso{cylinder, ellipsoid, rectangle} 53 ## @seealso{cylinder, ellipsoid, rectangle}
54 ## @end deftypefn 54 ## @end deftypefn
55 55
56 function [xx, yy, zz] = sphere (varargin) 56 function [x, y, z] = sphere (varargin)
57 57
58 [hax, varargin, nargin] = __plt_get_axis_arg__ ("sphere", varargin{:}); 58 [hax, varargin, nargin] = __plt_get_axis_arg__ ("sphere", varargin{:});
59 59
60 if (nargin > 1) 60 if (nargin > 1)
61 print_usage (); 61 print_usage ();
62 elseif (nargin == 1) 62 elseif (nargin == 1)
63 n = varargin{1}; 63 n = varargin{1};
64 if (! (isreal (n) && isscalar (n) && n > 0))
65 error ("sphere: N must be a real scalar > 0");
66 endif
64 else 67 else
65 n = 20; 68 n = 20;
66 endif 69 endif
67 70
68 theta = linspace (0, 2*pi, n+1); 71 theta = linspace (0, 2*pi, n+1);
69 phi = linspace (-pi/2, pi/2, n+1); 72 phi = linspace (-pi/2, pi/2, n+1);
70 [theta,phi] = meshgrid (theta, phi); 73 [theta, phi] = meshgrid (theta, phi);
71 74
72 x = cos (phi) .* cos (theta); 75 xx = cos (phi) .* cos (theta);
73 y = cos (phi) .* sin (theta); 76 yy = cos (phi) .* sin (theta);
74 z = sin (phi); 77 zz = sin (phi);
75 78
76 if (nargout > 0) 79 if (nargout > 0)
77 xx = x; 80 x = xx;
78 yy = y; 81 y = yy;
79 zz = z; 82 z = zz;
80 else 83 else
81 oldfig = []; 84 oldfig = [];
82 if (! isempty (hax)) 85 if (! isempty (hax))
83 oldfig = get (0, "currentfigure"); 86 oldfig = get (0, "currentfigure");
84 endif 87 endif
85 unwind_protect 88 unwind_protect
86 hax = newplot (hax); 89 hax = newplot (hax);
87 90
88 surf (x, y, z); 91 surf (xx, yy, zz);
89 unwind_protect_cleanup 92 unwind_protect_cleanup
90 if (! isempty (oldfig)) 93 if (! isempty (oldfig))
91 set (0, "currentfigure", oldfig); 94 set (0, "currentfigure", oldfig);
92 endif 95 endif
93 end_unwind_protect 96 end_unwind_protect
94 endif 97 endif
95 98
96 endfunction 99 endfunction
100
101
102 %!demo
103 %! clf;
104 %! colormap ("default");
105 %! [x, y, z] = sphere (40);
106 %! surf (3*x, 3*y, 3*z);
107 %! axis equal;
108 %! title ("sphere of radius 3");
109
110 ## Test input validation
111 %!error <Invalid call> sphere (-1,1)
112 %!error <N must be a real scalar> sphere (2i)
113 %!error <N must be a real scalar> sphere ([])
114 %!error <N must be a real scalar> sphere (ones (2,2))
115 %!error <N must be a real scalar . 0> sphere (-1)