pchfe pchia pchse

pchfe() def pchfe ( n  , x  , f  , d  , ne  , xe  , fe  , incfd  = 1, skip  = 0  ) Evaluation of function values for piecewise cubic Hermite (and cubic spline) interpolation Purpose pchfe evaluates a piecewise cubic Hermite function at an array of points. May be used by itself for Hermite interpolation, or as an evaluator for pchim, pchic, pchsp or pchse. Returns info (int) = 0: Successful exit = -1: The argument n had an illegal value (n < 2) = -2: The argument x is invalid (e.g. not strictly increasing) = -3: The argument f is invalid = -4: The argument d is invalid = -5: The argument incfd had an illegal value (incfd < 1) = -6: The argument skip had an illegal value (skip != 0 and skip != 1) = -7: The argument ne had an illegal value (ne < 1) = -8: The argument xe is invalid = -9: The argument fe is invalid = i > 0: Extrapolation was performed at i points Parameters [in] n Number of data points. (n >= 2) [in] x Numpy ndarray (1-dimensional, float, length n) Independent variable values. The elements of x[] must be strictly increasing. [in] f Numpy ndarray (1-dimensional, float, length incfd*(n - 1) + 1) Function values. f[i*incfd] is the value corresponding to x[i] (i = 0 to n - 1). [in] d Numpy ndarray (1-dimensional, float, length incfd*(n - 1) + 1) Derivative values. d[i*incfd] is the value corresponding to x[i] (i = 0 to n - 1). [in] ne Number of evaluation points. (ne >= 1) [in] xe Numpy ndarray (1-dimensional, float, length ne) Points at which the function is to be evaluated. Notes: The evaluation will be most efficient if the elements of xe are increasing relative to x; that is, xe[j] >= x[i] implies xe[k] >= x[i], all k >= j. If any of the xe[] are outside the interval [ x[0], x[n-1] ], values are extrapolated from the nearest extreme cubic, and a warning error is returned. [out] fe Numpy ndarray (1-dimensional, float, length ne) Values of the cubic Hermite function defined by n, x, f, d at the points xe. [in] incfd (Optional) Increment between successive values in f and d. (incfd >= 1) (default = 1) [in] skip (Optional) Logical variable which should be set to true (1) if the user wishes to skip checks for validity of preceding parameters, or to false (0) otherwise. This will save time in case these checks have already been performed (say, in pchim, pchic, pchsp or pchse). (default = 0) Reference SLATEC (PCHIP) Example Program See example of pchse.