[Ecls-list] (expt 2 #c(-2d0 -1d0)) is inaccurate

Raymond Toy toy.raymond at gmail.com
Tue Jun 1 22:21:26 UTC 2010


Although it seems the spec allows this, ecl produces an answer that only
has single-float accuracy for (expt 2 #c(-2d0 -1d0)).  I think the
issues arises because the result is computed as (exp (* #c(-2d0 -1d0)
(log 2))).  That (log 2) gives single-precision accuracy that is coerced
to double-float.

This issue causes some tests in maxima to fail.

(Should I use the bug tracker for this?)

Ray







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