LARRD: computes the eigenvalues of a symmetric tridiagonal matrix T to suitable accuracy. This is an auxiliary code to be called from DSTEMR. The user may ask for all eigenvalues, all eigenvalues in the half-open interval (VL, VU], or the IL-th through IU-th eigenvalues. To avoid overflow, the matrix must be scaled so that its largest element is no greater than overflow**(1/2) * underflow**(1/4) in absolute value, and for greatest accuracy, it should not be much smaller than that. See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal
Matrix", Report CS41, Computer Science Dept., Stanford University, July 21, 1966.
More...
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| pure subroutine | dlarrd (range, order, n, vl, vu, il, iu, gers, reltol, d, e, e2, pivmin, nsplit, isplit, m, w, werr, wl, wu, iblock, indexw, work, iwork, info) |
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| | la_dlarrd |
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| | la_qlarrd |
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| pure subroutine | slarrd (range, order, n, vl, vu, il, iu, gers, reltol, d, e, e2, pivmin, nsplit, isplit, m, w, werr, wl, wu, iblock, indexw, work, iwork, info) |
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| | la_slarrd |
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LARRD: computes the eigenvalues of a symmetric tridiagonal matrix T to suitable accuracy. This is an auxiliary code to be called from DSTEMR. The user may ask for all eigenvalues, all eigenvalues in the half-open interval (VL, VU], or the IL-th through IU-th eigenvalues. To avoid overflow, the matrix must be scaled so that its largest element is no greater than overflow**(1/2) * underflow**(1/4) in absolute value, and for greatest accuracy, it should not be much smaller than that. See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal
Matrix", Report CS41, Computer Science Dept., Stanford University, July 21, 1966.
◆ dlarrd()
| pure subroutine la_lapack::larrd::dlarrd |
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character, intent(in) | range, |
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character, intent(in) | order, |
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integer(ilp), intent(in) | n, |
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real(dp), intent(in) | vl, |
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real(dp), intent(in) | vu, |
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integer(ilp), intent(in) | il, |
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integer(ilp), intent(in) | iu, |
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real(dp), dimension(*), intent(in) | gers, |
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real(dp), intent(in) | reltol, |
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real(dp), dimension(*), intent(in) | d, |
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real(dp), dimension(*), intent(in) | e, |
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real(dp), dimension(*), intent(in) | e2, |
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real(dp), intent(in) | pivmin, |
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integer(ilp), intent(in) | nsplit, |
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integer(ilp), dimension(*), intent(in) | isplit, |
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integer(ilp), intent(out) | m, |
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real(dp), dimension(*), intent(out) | w, |
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real(dp), dimension(*), intent(out) | werr, |
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real(dp), intent(out) | wl, |
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real(dp), intent(out) | wu, |
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integer(ilp), dimension(*), intent(out) | iblock, |
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integer(ilp), dimension(*), intent(out) | indexw, |
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real(dp), dimension(*), intent(out) | work, |
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integer(ilp), dimension(*), intent(out) | iwork, |
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integer(ilp), intent(out) | info ) |
◆ la_dlarrd()
| la_lapack::larrd::la_dlarrd |
◆ la_qlarrd()
| la_lapack::larrd::la_qlarrd |
◆ la_slarrd()
| la_lapack::larrd::la_slarrd |
◆ slarrd()
| pure subroutine la_lapack::larrd::slarrd |
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character, intent(in) | range, |
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character, intent(in) | order, |
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integer(ilp), intent(in) | n, |
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real(sp), intent(in) | vl, |
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real(sp), intent(in) | vu, |
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integer(ilp), intent(in) | il, |
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integer(ilp), intent(in) | iu, |
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real(sp), dimension(*), intent(in) | gers, |
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real(sp), intent(in) | reltol, |
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real(sp), dimension(*), intent(in) | d, |
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real(sp), dimension(*), intent(in) | e, |
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real(sp), dimension(*), intent(in) | e2, |
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real(sp), intent(in) | pivmin, |
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integer(ilp), intent(in) | nsplit, |
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integer(ilp), dimension(*), intent(in) | isplit, |
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integer(ilp), intent(out) | m, |
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real(sp), dimension(*), intent(out) | w, |
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real(sp), dimension(*), intent(out) | werr, |
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real(sp), intent(out) | wl, |
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real(sp), intent(out) | wu, |
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integer(ilp), dimension(*), intent(out) | iblock, |
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integer(ilp), dimension(*), intent(out) | indexw, |
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real(sp), dimension(*), intent(out) | work, |
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integer(ilp), dimension(*), intent(out) | iwork, |
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integer(ilp), intent(out) | info ) |
The documentation for this interface was generated from the following file:
