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ChebyshevFirst1D example 5

This example shows the usage of [[ChebyshevFirst1D_]] class. We test EvalGradient in this routine. the argument of EvalGradient is vector in this routine.

Modules and classes​

  • [[ChebyshevFirst1D_]]

Usage​

PROGRAM main
use easifemBase
use easifemClasses
implicit none
type(ChebyshevFirst1D_) :: obj
type(String) :: astr
integer(i4b) :: ii, n
real( dfp ), allocatable :: x(:), yexact(:), y(:)
real( dfp ) :: tol=1.0E-10

n=1​

  x = linspace(0.0_DFP, 1.0_DFP, 11_I4B)
  yexact = ones(11, 1)
  n=1
  obj = ChebyshevFirst1D(varname="x", n=n)
  y = obj%EvalGradient( x )
  call OK( ALL( y .APPROXEQ. yexact), "test-1:" )

n=2​

  yexact = 4.0*x
  n=2
  obj = ChebyshevFirst1D(varname="x", n=n)
  y = obj%EvalGradient( x )
  call OK(ALL(y .APPROXEQ. yexact), "test-2:" )

n=3​

  yexact = 12.0*x**2 - 3.0
  n=3
  obj = ChebyshevFirst1D(varname="x", n=n)
  y = obj%EvalGradient( x )
  call OK(ALL( SOFTEQ( y, yexact, tol=tol )), "test-3:" )

n=4​

  yexact = 32.0*x**3 - 16.0*x
  n=4
  obj = ChebyshevFirst1D(varname="x", n=n)
  y = obj%EvalGradient( x )
  call OK(ALL( SOFTEQ( y, yexact, tol=tol )), "test-4:"  )
END PROGRAM main