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[Octave-bug-tracker] [bug #45507] acos returns different results on big
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From: |
Marco Caliari |
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Subject: |
[Octave-bug-tracker] [bug #45507] acos returns different results on big input values |
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Date: |
Thu, 16 Jul 2015 10:04:59 +0000 |
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User-agent: |
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:39.0) Gecko/20100101 Firefox/39.0 |
Follow-up Comment #3, bug #45507 (project octave):
Hi, I'm on 3.8.2, and I see several discrepancies or NaN (try, e.g.,
asin(1e8)). Some of them are related to the evaluation of quantities like
z+sqrt(z^2-1) which, for large negative numbers z, are z+|z| and therefore 0.
Moreover, sqrt(z^2-1) may overflow for z>sqrt(realmax). So, I wrote a test
file for acos, asin, acosh and asinh. If I run it on Matlab 2014, the results
are always correct. The test file should help in the correct implementation.
Marco
(file #34451)
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File name: testx3.m Size:2 KB
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