06 October 2025   6:21:08.120 PM

lagrange_interp_nd_test():
  Fortran90 version
  Test lagrange_interp_nd().
  The R8LIB library is needed.

TEST01:
  Interpolate in 1D, using orders.
  LAGRANGE_INTERP_ND_GRID sets the interpolant.
  LAGRANGE_INTERP_ND_VALUE evaluates it.

         Zinterp          Zexact      Error

    0.146316        0.146316        0.92E-07
    0.684153        0.684173        0.20E-04
    0.225810        0.225791        0.18E-04
    0.673525        0.673547        0.22E-04
    0.440495        0.440485        0.97E-05

TEST02:
  Interpolate in 2D, using orders.
  LAGRANGE_INTERP_ND_GRID sets the interpolant.
  LAGRANGE_INTERP_ND_VALUE evaluates it.

         Zinterp          Zexact      Error

    0.545315        0.544330        0.99E-03
    0.683253        0.679833        0.34E-02
    0.600082        0.596701        0.34E-02
    0.840111        0.840792        0.68E-03
    0.724333        0.722277        0.21E-02

TEST03:
  Interpolate in 3D, using orders.
  LAGRANGE_INTERP_ND_GRID sets the interpolant.
  LAGRANGE_INTERP_ND_VALUE evaluates it.

         Zinterp          Zexact      Error

    0.762935        0.762107        0.83E-03
    0.672890        0.671411        0.15E-02
    0.853328        0.853430        0.10E-03
    0.561289        0.560898        0.39E-03
    0.784962        0.785889        0.93E-03

TEST04:
  Interpolate in 3D, using orders.
  Use a sequence of increasing orders.

  Level     Order   Average Error

      0         1    0.42E-01
      1        27    0.44E-02
      2       125    0.21E-03
      3       729    0.66E-04
      4      4913    0.94E-06
      5     35937    0.46E-07

TEST05:
  Repeat test #1, using levels.
  LAGRANGE_INTERP_ND_GRID2 sets the interpolant.
  LAGRANGE_INTERP_ND_VALUE2 evaluates it.

         Zinterp          Zexact      Error

    0.718120        0.718131        0.12E-04
    0.672490        0.672512        0.22E-04
    0.791227        0.791216        0.10E-04
    0.410600        0.410584        0.16E-04
    0.659090        0.659114        0.24E-04

TEST06:
  Repeat test #2, using levels.
  LAGRANGE_INTERP_ND_GRID2 sets the interpolant.
  LAGRANGE_INTERP_ND_VALUE2 evaluates it.

         Zinterp          Zexact      Error

    0.630123        0.626357        0.38E-02
    0.692704        0.692279        0.43E-03
    0.954572        0.954597        0.25E-04
    0.897800        0.897807        0.70E-05
    0.704940        0.704647        0.29E-03

TEST07:
  Repeat test #3,  using levels.
  LAGRANGE_INTERP_ND_GRID2 sets the interpolant.
  LAGRANGE_INTERP_ND_VALUE2 evaluates it.

         Zinterp          Zexact      Error

    0.994671        0.994572        0.99E-04
    0.545132        0.544200        0.93E-03
    0.953068        0.953503        0.43E-03
    0.368486        0.372898        0.44E-02
    0.890709        0.891005        0.30E-03

TEST08:
  Interpolate in 3D, using levels.
  Use a sequence of increasing levels.

  Level     Order   Average Error

      0         1    0.37E-01
      1        27    0.44E-02
      2       125    0.23E-03
      3       729    0.79E-05
      4      4913    0.23E-06
      5     35937    0.14E-08

TEST09:
  Interpolate in 3D, using orders.
  Use a sequence of increasing orders.
  Use anisotropic resolution.
  The interpolant is a polynomial of degrees 3, 5, 2
  so our orders need to be at least 4, 6, 3 to match it.

  Level     Orders   Average Error

      0      1      1      1    0.92E-01
      1      2      1      1    0.69E-01
      2      1      2      1    0.78E-01
      3      1      1      2    0.91E-01
      4      4      2      2    0.38E-01
      5      2      4      2    0.73E-01
      6      2      2      4    0.94E-01
      7      2      2      4    0.94E-01
      8      6      4      4    0.49E-03
      9      4      6      4    0.15E-15
     10      4      4      6    0.49E-03

lagrange_interp_nd_test():
  Normal end of execution.

06 October 2025   6:21:08.138 PM