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From: <me...@ar...> - 2005-10-17 21:10:05
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Hi there- I have a question on how this difference arises when I run the following simple code on windows and Debian: >>> from numarray import * >>> a=reshape(arange(81.0), (9,9))+identity(9) >>> ca = matrixmultiply(transpose(a),a) >>> import numarray.linear_algebra as la >>> ica = la.inverse(ca) >>> ica.min() -0.30951621414374736 >>> ica.max() 0.8888918586585135 The above is the result in Debian and below is that in Windows: >>> ica.min() -0.30951621414449404 >>> ica.max() 0.88889185865875686 So, what caused this difference (both machines have python2.4 and numarray 1.3.2)? The difference happens in the 10th/11th decimal point, which should be still in the floating point precision, right? This simple difference caused big differences in my later calculation. Best, Xiangyi |