1spline(1)                        User Commands                       spline(1)
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NAME

6       spline - interpolate smooth curve
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SYNOPSIS

9       spline [-aknpx] ...
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DESCRIPTION

13       spline  takes  pairs of numbers from the standard input as abcissas and
14       ordinates of a function. It produces a similar set, which  is  approxi‐
15       mately  equally spaced and includes the input set, on the standard out‐
16       put. The cubic spline output (R. W. Hamming, Numerical Methods for Sci‐
17       entists  and  Engineers,2nd ed., 349ff) has two continuous derivatives,
18       and sufficiently many points to look smooth when plotted,  for  example
19       by graph(1).
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OPTIONS

22       -a    Supply abscissas automatically (they are missing from the input);
23             spacing is given by the next argument, or is assumed to be  1  if
24             next argument is not a number.
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27       -k    The constant k used in the boundary value computation
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29             (2nd deriv. at end) = k*(2nd deriv. next to end)
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31             is set by the next argument. By default k = 0.
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34       -n    Space  output  points  so  that  approximately  n intervals occur
35             between the lower and upper x limits.  (Default n = 100.)
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38       -p    Make output periodic, that is, match derivatives at  ends.  First
39             and last input values should normally agree.
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42       -x    Next 1 (or 2) arguments are lower (and upper) x limits.  Normally
43             these limits are calculated from  the  data.  Automatic  abcissas
44             start at lower limit (default 0).
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ATTRIBUTES

48       See attributes(5) for descriptions of the following attributes:
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53       ┌─────────────────────────────┬─────────────────────────────┐
54       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
55       ├─────────────────────────────┼─────────────────────────────┤
56       │Availability                 │SUNWesu                      │
57       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

60       graph(1), attributes(5)
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63       R. W. Hamming, Numerical Methods for Scientists and Engineers, 2nd ed.
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DIAGNOSTICS

66       When  data  is not strictly monotonic in x, spline reproduces the input
67       without interpolating extra points.
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BUGS

70       A limit of 1000 input points is enforced silently.
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74SunOS 5.11                        14 Sep 1992                        spline(1)