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| author | Wojtek Kosior <kwojtus@protonmail.com> | 2019-06-21 13:22:58 +0200 |
|---|---|---|
| committer | Wojtek Kosior <kwojtus@protonmail.com> | 2019-06-21 13:22:58 +0200 |
| commit | 00e4d345ac3a40e7d1d18df7cf751833cd608612 (patch) | |
| tree | 94e22d92a6dd758184797a66a150d2e5d21ab3f2 | |
| parent | 7d28fe599e1a5498a7e86dc04fa207cab11559ac (diff) | |
| download | fortran-assignment3-00e4d345ac3a40e7d1d18df7cf751833cd608612.tar.gz fortran-assignment3-00e4d345ac3a40e7d1d18df7cf751833cd608612.zip | |
compozite newton-cotes integration
| -rw-r--r-- | src/quadratures.f90 | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/src/quadratures.f90 b/src/quadratures.f90 index a3f869f..9be7517 100644 --- a/src/quadratures.f90 +++ b/src/quadratures.f90 @@ -45,9 +45,13 @@ CONTAINS real(kind=8), intent(in) :: iend procedure(funint) :: fun integer(kind=4), intent(in) :: p - real(kind=8) :: val + + real(kind=8) :: val, subinterval_width, qbeg, qend procedure(quadrature), pointer :: quad + integer(kind=8) :: i + + subinterval_width = (iend - ibeg) / subintervals SELECT CASE (p) CASE (:-1) @@ -63,7 +67,13 @@ CONTAINS END SELECT ! compute integral using quadrature pointed by quad - val = quad(ibeg, iend, fun) + val = 0 + + DO i = 1, subintervals + qend = ibeg + i * subinterval_width + qbeg = ibeg + (i - 1) * subinterval_width + val = val + quad(qbeg, qend, fun) + END DO END FUNCTION newton_cotes FUNCTION rectangle(qbeg, qend, fun) result(val) |