LegendreGradientEval

Evaluate gradient of Legendre polynomials.

Interface 1

܀ Interface

INTERFACE
  MODULE PURE FUNCTION LegendreGradientEval(n, x) RESULT(ans)
    INTEGER(I4B), INTENT(IN) :: n
    REAL(DFP), INTENT(IN) :: x
    REAL(DFP) :: ans
  END FUNCTION LegendreGradientEval
END INTERFACE

️܀ See example

This example shows the usage of LegendreGradientEval method.

This routine evaluates gradient of Legendre polynomial of order n, at single point.

program main
  use easifembase
  implicit none
  integer( i4b ) :: n
  real( dfp ) :: ans, x, exact
  real( dfp ), parameter :: tol=1.0E-10
  n = 3
  x = -1.0_DFP; call callme
  exact = 0.5_DFP*(3*5.0 * x**2 - 3.0)
  call ok( SOFTEQ(ans, exact, tol ))
  x = 0.0_DFP; call callme
  exact = 0.5_DFP*(3*5.0 * x**2 - 3.0)
  call ok( SOFTEQ(ans, exact, tol ))
  x = +1.0_DFP; call callme
  exact = 0.5_DFP*(3*5.0 * x**2 - 3.0)
  call ok( SOFTEQ(ans, exact, tol ))
  contains
  subroutine callme
    ans= LegendreGradientEval( n=n, x=x )
  end subroutine callme
end program main

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Interface 2

܀ Interface

INTERFACE
  MODULE PURE FUNCTION LegendreGradientEval(n, x) RESULT(ans)
    INTEGER(I4B), INTENT(IN) :: n
    REAL(DFP), INTENT(IN) :: x(:)
    REAL(DFP) :: ans(1:SIZE(x))
  END FUNCTION LegendreGradientEval
END INTERFACE

️܀ See example

See above example.

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