CFD Utilities Files

GRADIENT_BASED Description:

   This is a driving program for subroutines GRADDIS2 and GRADDIS and their
   3-space analogues, which are intended to redistribute grid points along
   a 2- or 3-space line or curve based on the gradient magnitudes of the
   function accompanying the (x,y[,z]) points.

   It was prompted by a desire to thin the line-of-sight data used to
   perform radiative heating calculations via NEQAIR, in a somewhat
   intelligent way.

Input data format:

   x1  y1  [z1] f1
   x2  y2  [z2] f2     Arc lengths along this curve will be redistributed
   :   :   :    :
   xn  yn  [zn] fn

Output:
   X1  Y1  [z1] F1
   X2  Y2  [z2] F2     Here, m is probably less than n, but not necessarily
   :   :   :    :
   Xm  Ym  [zm] Fm

   Chances are that multiple functions will need to be interpolated to the
   new coordinates, but interpolating the driving function tests the new
   variant of LCSFIT (LCSFIT2, which normalizes the data beforehand).

History:

   11/21/2013  D.A.Saunders  Initial test program for GRADDIS[2] ...
   11/22/2013    "      "    ... and for LCSFIT2 (interpln. w/ normalzn.).
   12/02/2013    "      "    Added the 3-space option.

Author:  David Saunders, ERC Inc. at NASA Ames Research Center, CA