1`SPLINE(1G) SPLINE(1G)`

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6` spline - interpolate smooth curve`

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9` spline [ option ] ...`

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12` Spline takes pairs of numbers from the standard input as abcissas and`

13` ordinates of a function. It produces a similar set, which is approxi‐`

14` mately equally spaced and includes the input set, on the standard out‐`

15` put. The cubic spline output (R. W. Hamming, Numerical Methods for`

16` Scientists and Engineers, 2nd ed., 349ff) has two continuous deriva‐`

17` tives, and sufficiently many points to look smooth when plotted, for`

18` example by graph(1).`

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20` The following options are recognized, each as a separate argument.`

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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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26` -k The constant k used in the boundary value computation`

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28` (2nd deriv. at end) = k*(2nd deriv. next to end)`

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30` is set by the next argument. By default k = 0.`

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32` -n Space output points so that approximately n intervals occur`

33` between the lower and upper x limits. (Default n = 100.)`

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35` -p Make output periodic, i.e. match derivatives at ends. First and`

36` last input values should normally agree.`

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38` -x Next 1 (or 2) arguments are lower (and upper) x limits. Normally`

39` these limits are calculated from the data. Automatic abcissas`

40` start at lower limit (default 0).`

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43` graph(1)`

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46` When data is not strictly monotone in x, spline reproduces the input`

47` without interpolating extra points.`

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50` A limit of 1000 input points is enforced silently.`

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54` SPLINE(1G)`