Tue, 24 Mar 2009 13:15:21 -0400, Darren Dale wrote: > I just performed an svn update, deleted my old build/ and > site-packages/numpy*, reinstalled, and I see a new test failure on a 64 > bit linux machine: > > ====================================================================== > FAIL: test_umath.TestComplexFunctions.test_loss_of_precision_longcomplex > ---------------------------------------------------------------------- [clip] > "/usr/lib64/python2.6/site-packages/numpy/core/tests/test_umath.py", > line 497, in check > 'arctanh') > AssertionError: (135, 3.4039637354191726288e-09, > 3.9031278209478159624e-18, 'arctanh')
I can reproduce this (on another 64-bit machine). This time around, it's the real function that is faulty: >>> x = np.longdouble(3e-9) >>> np.arctanh(x+0j).real - x 9.0876776281460559983e-27 >>> np.arctanh(x).real - x 0.0 >>> np.finfo(np.longdouble).eps * x 3.2526065174565132804e-28 So, the system atanhl is ~ 30 relative eps away from the correct answer: >>> from sympy import mpmath >>> mpmath.mp.dps=60 >>> p = mpmath.mpf('3e-9') >>> print (mpmath.atanh(p) - p)*1e27 9.00000000000000016818799564800000095820042512435586643130912 I'll relax the test tolerance to allow for this... -- Pauli Virtanen _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion