1rbox(1)                     General Commands Manual                    rbox(1)
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NAME

6       rbox - generate point distributions for qhull
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SYNOPSIS

9       Command "rbox" (w/o arguments) lists the options.
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DESCRIPTION

12       rbox generates random or regular points according to the options given,
13       and outputs the points to stdout. The points are generated in  a  cube,
14       unless  's'  or   'k'  option is given. The format of the output is the
15       following: first line contains the dimension and a comment, second line
16       contains  the  number  of  points,  and the following lines contain the
17       points, one point per line. Points are represented by their  coordinate
18       values.
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EXAMPLES

21       rbox 10
22              10 random points in the unit cube centered at the origin.
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24       rbox 10 s D2
25              10 random points on a 2‐d circle.
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27       rbox 100 W0
28              100 random points on the surface of a cube.
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30       rbox 1000 s D4
31              1000 random points on a 4‐d sphere.
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33       rbox c D5 O0.5
34              a 5‐d hypercube with one corner at the origin.
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36       rbox d D10
37              a 10‐d diamond.
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39       rbox x 1000 r W0
40              100 random points on the surface of a fixed simplex
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42       rbox y D12
43              a 12‐d simplex.
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45       rbox l 10
46              10 random points along a spiral
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48       rbox l 10 r
49              10 regular points along a spiral plus two end points
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51       rbox 1000 L10000 D4 s
52              1000 random points on the surface of a narrow lens.
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54       rbox c G2 d G3
55              a  cube  with  coordinates  +2/-2 and a diamond with coordinates
56              +3/-3.
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58       rbox 64 M3,4 z
59              a rotated, {0,1,2,3} x {0,1,2,3} x {0,1,2,3} lattice  (Mesh)  of
60              integer points. 'rbox 64 M1,0' is orthogonal.
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62       rbox P0 P0 P0 P0 P0
63              5 copies of the origin in 3-d.  Try 'rbox P0 P0 P0 P0 P0 | qhull
64              QJ'.
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66       r 100 s Z1 G0.1
67              two cospherical 100-gons plus another cospherical point.
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69       100 s Z1
70              a cone of points.
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72       100 s Z1e-7
73              a narrow cone of points with many precision errors.
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OPTIONS

76       n      number of points
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78       Dn     dimension n‐d (default 3‐d)
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80       Bn     bounding box coordinates (default 0.5)
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82       l      spiral distribution, available only in 3‐d
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84       Ln     lens distribution of radius n.  May be used with 's', 'r',  'G',
85              and 'W'.
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87       Mn,m,r lattice  (Mesh)  rotated  by  {[n,-m,0], [m,n,0], [0,0,r], ...}.
88              Use 'Mm,n' for a rigid rotation with r = sqrt(n^2+m^2).   'M1,0'
89              is  an  orthogonal lattice.  For example, '27 M1,0' is {0,1,2} x
90              {0,1,2} x {0,1,2}. '27 M3,4 z' is a rotated integer lattice.
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92       s      cospherical points randomly generated in a cube and projected to
93              the unit sphere
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95       x      simplicial  distribution.   It  is fixed for option 'r'.  May be
96              used with 'W'.
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98       y      simplicial distribution plus a simplex.  Both 'x' and 'y' gener‐
99              ate the same points.
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101       Wn     restrict  points  to  distance n of the surface of a sphere or a
102              cube
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104       c      add a unit cube to the output
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106       c Gm   add a cube with all combinations of +m and -m to the output
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108       d      add a unit diamond to the output.
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110       d Gm   add a diamond made of 0, +m and -m to the output
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112       Cn,r,m add n nearly coincident points within radius r of m points
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114       Pn,m,r add point [n,m,r] to the output  first.   Pad  coordinates  with
115              0.0.
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117       n      Remove the command line from the first line of output.
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119       On     offset the data by adding n to each coordinate.
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121       t      use  time  in seconds as the random number seed (default is com‐
122              mand line).
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124       tn     set the random number seed to n.
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126       z      generate integer coordinates.  Use 'Bn'  to  change  the  range.
127              The default is 'B1e6' for six‐digit coordinates.  In R^4, seven‐
128              digit coordinates will overflow hyperplane normalization.
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130       Zn s   restrict points to a disk about  the  z+  axis  and  the  sphere
131              (default  Z1.0).  Includes the opposite pole.  'Z1e-6' generates
132              degenerate points under single precision.
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134       Zn Gm s
135              same as Zn with an empty center (default G0.5).
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137       r s D2 generate a regular polygon
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139       r s Z1 G0.1
140              generate a regular cone
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BUGS

143       Some combinations of arguments generate odd results.
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145       Report   bugs   to   qhull_bug@qhull.org,   other   correspondence   to
146       qhull@qhull.org
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SEE ALSO

149       qhull(1)
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AUTHOR

152       C. Bradford Barber
153       bradb@shore.net
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158Geometry Center                 August 10, 1998                        rbox(1)
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