root / synthbench / euroben-dm / mod2ci / .svn / text-base / rotb.f.svn-base @ 0:839f52ef7657
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Subroutine rotb( arg, c, s ) |
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! ---------------------------------------------------------------------- |
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! --- Stores rotation factors arg according to sine/cosine terms of |
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! Givens transformation (used in rgmres). |
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! ---------------------------------------------------------------------- |
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Use numerics |
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Use floptime |
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Implicit None |
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|
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Real(l_) :: arg, c, s |
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! ---------------------------------------------------------------------- |
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If ( c == 0.0_l_ ) Then |
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arg = 1.0_l_ |
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Else If ( Abs( s ) < Abs( c ) ) Then |
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arg = 0.5_l_*s*Sign( 1.0_l_, c ) |
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flops = flops + 6 |
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Else |
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arg = 2.0_l_*Sign( 1.0_l_, s )/c |
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flops = flops + 6 |
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End If |
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! ---------------------------------------------------------------------- |
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End Subroutine rotb |