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module invert_zoom_x_m |
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|
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implicit none |
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|
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INTEGER, PARAMETER:: nmax = 30000 |
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|
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contains |
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|
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subroutine invert_zoom_x(xf, xtild, G, xlon, xprimm, xuv) |
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|
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use coefpoly_m, only: coefpoly |
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USE dimens_m, ONLY: iim |
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use dynetat0_m, only: clon |
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use nr_util, only: pi_d, twopi_d |
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use numer_rec_95, only: hunt |
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|
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DOUBLE PRECISION, intent(in):: Xf(0:), xtild(0:), G(0:) ! (0:nmax) |
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|
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real, intent(out):: xlon(:), xprimm(:) ! (iim) |
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|
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DOUBLE PRECISION, intent(in):: xuv |
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! between - 0.25 and 0.5 |
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! 0. si calcul aux points scalaires |
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! 0.5 si calcul aux points U |
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|
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! Local: |
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DOUBLE PRECISION xo1, Xfi, abs_xfi, a0, a1, a2, a3, Xf1, Xprimin |
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integer i, it, iter |
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DOUBLE PRECISION, parameter:: my_eps = 1d-6 |
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|
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DOUBLE PRECISION xxprim(iim), xvrai(iim) |
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! intermediary variables because xlon and xprimm are simple precision |
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|
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!------------------------------------------------------------------ |
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|
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it = 0 ! initial guess |
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|
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DO i = 1, iim |
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Xfi = - pi_d + (i + xuv - 0.75d0) * twopi_d / iim |
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! - pi <= xfi < pi |
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abs_xfi = abs(xfi) |
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|
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call hunt(xf, abs_xfi, it, my_lbound = 0) |
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! {0 <= it <= nmax - 1} |
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|
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! Calcul de xvrai(i) et xxprim(i) |
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|
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CALL coefpoly(Xf(it), Xf(it + 1), G(it), G(it + 1), xtild(it), & |
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xtild(it + 1), a0, a1, a2, a3) |
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xvrai(i) = xtild(it) |
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Xf1 = Xf(it) |
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Xprimin = G(it) |
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xo1 = xvrai(i) |
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iter = 1 |
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|
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do |
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xvrai(i) = xvrai(i) - (Xf1 - abs_xfi) / Xprimin |
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IF (ABS(xvrai(i) - xo1) <= my_eps .or. iter == 300) exit |
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xo1 = xvrai(i) |
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Xf1 = a0 + xvrai(i) * (a1 + xvrai(i) * (a2 + xvrai(i) * a3)) |
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Xprimin = a1 + xvrai(i) * (2d0 * a2 + xvrai(i) * 3d0 * a3) |
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end DO |
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|
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if (ABS(xvrai(i) - xo1) > my_eps) then |
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! iter == 300 |
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print *, 'Pas de solution.' |
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print *, i, abs_xfi |
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STOP 1 |
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end if |
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|
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if (xfi < 0) xvrai(i) = - xvrai(i) |
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xxprim(i) = twopi_d / (iim * Xprimin) |
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end DO |
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|
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DO i = 1, iim -1 |
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IF (xvrai(i + 1) < xvrai(i)) THEN |
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print *, 'xvrai(', i + 1, ') < xvrai(', i, ')' |
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STOP 1 |
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END IF |
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END DO |
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|
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xlon = xvrai + clon |
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xprimm = xxprim |
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|
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end subroutine invert_zoom_x |
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|
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end module invert_zoom_x_m |