New submission from Andreas Kloeckner: This here basically says it all:
>>> import cmath;[cmath.asinh(i*1e-17).real for i in range(0,20)] [4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16, 4.4408920985006257e-16] The boost.math toolkit at [2] is an implementation that does better in the above (real-only) aspect. [2] http://freespace.virgin.net/boost.regex/toolkit/html/index.html Tim Peters remarks in [1] that basically all of cmath is unsound. http://mail.python.org/pipermail/python-bugs-list/2001-February/004126.html I just wanted to make sure that this issue remains on the radar. ---------- components: Library (Lib) messages: 57088 nosy: inducer severity: normal status: open title: cmath is numerically unsound type: behavior versions: Python 2.5 __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue1381> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
