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module inifgn_m |
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use dimens_m, only: iim |
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IMPLICIT NONE |
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private iim |
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real sddu(iim), sddv(iim) ! SQRT(dx / di) |
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real unsddu(iim), unsddv(iim) |
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real eignfnu(iim, iim), eignfnv(iim, iim) |
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! eigenfunctions of the discrete laplacian |
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contains |
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SUBROUTINE inifgn(dv) |
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! From LMDZ4/libf/filtrez/inifgn.F, v 1.1.1.1 2004/05/19 12:53:09 |
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! H. Upadyaya, O. Sharma |
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use acc_m, only: acc |
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USE dimens_m, ONLY: iim |
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USE dynetat0_m, ONLY: xprimu, xprimv |
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use numer_rec_95, only: jacobi, eigsrt |
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real, intent(out):: dv(:) ! (iim) eigenvalues sorted in descending order |
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! Local: |
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REAL, dimension(iim, iim):: a, b, c |
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REAL du(iim) |
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INTEGER i |
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!---------------------------------------------------------------- |
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print *, "Call sequence information: inifgn" |
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sddv = sqrt(xprimv(:iim)) |
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sddu = sqrt(xprimu(:iim)) |
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unsddu = 1. / sddu |
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unsddv = 1. / sddv |
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b = 0. |
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b(iim, 1) = unsddu(iim) * unsddv(1) |
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forall (i = 1:iim) b(i, i) = - unsddu(i) * unsddv(i) |
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forall (i = 1:iim - 1) b(i, i + 1) = unsddu(i) * unsddv(i + 1) |
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c = - transpose(b) |
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a = matmul(c, b) |
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CALL jacobi(a, dv, eignfnv) |
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CALL acc(eignfnv) |
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CALL eigsrt(dv, eignfnv) |
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a = matmul(b, c) |
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CALL jacobi(a, du, eignfnu) |
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CALL acc(eignfnu) |
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CALL eigsrt(du, eignfnu) |
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END SUBROUTINE inifgn |
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end module inifgn_m |
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