banfac banslv bint4 bintk bspldr bsplev bsplpp bsplvd bsplvn bvalue interv ppvalu

bsplpp() void bsplpp ( double  t[], double  a[], int  n, int  k, int  ldc, double  c[], double  xi[], int *  lxi, double  work[], int *  info  ) B-representation to PP (piecewise polynomial) form of B-spline conversion Purpose This routine converts the B-representation (t[], a[], n, k) of a B-spline to the PP (piecewise polynomial) form (c[][], xi[], lxi, k) for use with ppvalu. Here xi[], the break point array of length lxi, is the knot array t[] with multiplicities removed. The columns of the matrix c[j][i] contain the right Taylor derivatives for the polynomial expansion about xi[j] for the intervals xi[j] <= x <= xi[j+1], i = 0 to k-1, j = 0 to lxi-1. Function ppvalu makes this evaluation at a specified point x in xi[0] <= x <= xi[lxi]. Parameters [in] t[] Array t[lt] (lt >= n + k) Knot vector. [in] a[] Array a[la] (la >= n) B-spline coefficients. [in] n Number of B-spline coefficients. (n = sum of knot multiplicities - k) [in] k Order of B-spline. (k >= 1) [in] ldc Leading dimension of the two dimensional array c[][]. (ldc >= k) [out] c[][] Array c[lc][ldc] (lc >= lxi) Right derivatives at break points. [in] xi[] Array xi[l_xi] (l_xi >= lxi + 1) Break points. [out] lxi Number of polynomial pieces. (lxi <= n - k + 1) [out] work[] Array work[lwork] (lwork >= k*(n + 3)) Work array. [out] info = 0: Successful exit = -3: The argument n had an illegal value (n < k) = -4: The argument k had an illegal value (k < 1) = -5: The argument ldc had an illegal value (ldc < k) Reference SLATEC