bfqad bfqad_r bsqad pchia pchid pfqad pfqad_r ppqad

pchia() double pchia ( int  n, double  x[], double  f[], double  d[], int  incfd, int  skip, double  a, double  b, int *  info  ) Integral of piecewise cubic Hermite / cubic spline function Purpose This routine evaluates the definite integral of a piecewise cubic Hermite function over an arbitrary interval. The interpolant is defined by n, x[], f[] and d[] computed by pchim, pchic, pchsp or pchse. Returns Value of the requested integral. Parameters [in] n Number of data points. (n >= 2) [in] x[] Array x[lx] (lx >= n) Independent variable values. The elements of x[] must be strictly increasing. [in] f[] Array f[lf] (lf >= incfd*(n - 1) + 1) Function values. f[i*incfd] is the value corresponding to x[i] (i = 0 to n - 1). [in] d[] Array d[ld] (ld >= incfd*(n - 1) + 1) Derivative values. d[i*incfd] is the value corresponding to x[i] (i = 0 to n - 1). [in] incfd Increment between successive values in f[] and d[]. (incfd >= 1) [in] skip 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). [in] a Lower limit of integration. [in] b Upper limit of integration. Note - There is no requirement that [a, b] be contained in [x[0], x[n - 1]]. However, the resulting integral value will be highly suspect, if not. [out] info = 0: Successful exit = -1: The argument n had an illegal value (n < 2) = -2: The argument x had an illegal value (not distinct or not in increasing order) = -5: The argument incfd had an illegal value (incfd < 1) = 1: a is outside the interval [x[0], x[n-1]] = 2: b is outside the interval [x[0], x[n-1]] = 3: Both of the above are true Reference SLATEC (PCHIP)