7 September 2021  11:29:44.183 AM
 
CHEBYSHEV_TEST
  FORTRAN90 version.
  Test CHEBYSHEV.
 
CHEBYSHEV_TEST01
  CHEBYSHEV_COEFFICIENTS computes the coefficients of the
  Chebyshev interpolant.
  CHEBYSHEV_INTERPOLANT evaluates the interpolant.
 
  F(X) is a trig function:
 
      X           C(I)        F(X)       C(F)(X)
 
   -0.951057   -0.000000   -0.424215   -0.424215
   -0.587785    0.593826   -0.576453   -0.576453
    0.000000   -0.000000    0.000000    0.000000
    0.587785   -0.239113    0.576453    0.576453
    0.951057    0.000000    0.424215    0.424215
 
  Consider the same F(X), but now over [0,3]:
 
      X           C(I)        F(X)       C(F)(X)
 
    0.073415    0.316211    0.571335    0.571335
    0.618322   -0.000000    0.323929    0.323929
    1.500000    0.689696   -1.000000   -1.000000
    2.381678    0.000000    0.323929    0.323929
    2.926585   -0.468409    0.571335    0.571335
 
  Consider the same F(X), but now with higher order:
 
      X           C(I)        F(X)       C(F)(X)
 
   -0.987688   -0.000000   -0.115428   -0.115428
   -0.891007    0.446342   -0.662900   -0.662900
   -0.707107    0.000000    0.099041    0.099041
   -0.453990   -0.333248   -0.869792   -0.869792
   -0.156434   -0.000000   -0.552029   -0.552029
    0.156434    0.275317    0.552029    0.552029
    0.453990    0.000000    0.869792    0.869792
    0.707107   -0.411266   -0.099041   -0.099041
    0.891007   -0.000000    0.662900    0.662900
    0.987688   -0.233073    0.115428    0.115428
 
  F(X) is a degree 4 polynomial:
 
      X           C(I)        F(X)       C(F)(X)
 
   -0.987688  -14.250000  -15.948947  -15.948947
   -0.891007    8.750000  -15.430394  -15.430394
   -0.707107   -1.000000  -13.967514  -13.967514
   -0.453990   -0.750000  -11.289025  -11.289025
   -0.156434    0.125000   -7.782111   -7.782111
    0.156434    0.000000   -4.363522   -4.363522
    0.453990    0.000000   -1.862659   -1.862659
    0.707107   -0.000000   -0.532486   -0.532486
    0.891007   -0.000000   -0.072431   -0.072431
    0.987688   -0.000000   -0.000911   -0.000911
 
  The polynomial approximation to F(X) decays:
 
      X           C(I)        F(X)       C(F)(X)
 
   -0.987688    2.532132    0.372437    0.372437
   -0.891007    1.130318    0.410243    0.410243
   -0.707107    0.271495    0.493069    0.493069
   -0.453990    0.044337    0.635089    0.635089
   -0.156434    0.005474    0.855188    0.855188
    0.156434    0.000543    1.169334    1.169334
    0.453990    0.000045    1.574583    1.574583
    0.707107    0.000003    2.028115    2.028115
    0.891007    0.000000    2.437582    2.437582
    0.987688    0.000000    2.685020    2.685020
 
CHEBYSHEV_TEST
  Normal end of execution.
 
 7 September 2021  11:29:44.184 AM