From bug-octave-request at bevo dot che dot wisc dot edu Tue Dec 10 13:10:29 2002 Subject: RE: 0*NaN within matrix multiplication From: "Lippert, Ross A." To: "Schloegl Alois" , Date: Tue, 10 Dec 2002 14:10:15 -0500 Why is this a bug? Since when did (y*B)' == B'*y' in inexact arithmetic? -r -----Original Message----- From: Schloegl Alois [mailto:alois dot schloegl at tugraz dot at] Sent: Tuesday, December 10, 2002 1:39 PM To: bug-octave at bevo dot che dot wisc dot edu Subject: 0*NaN within matrix multiplication octave> x=[-2:2;4:8]'; octave> y=x;y(2,1)=nan;y(4,2)=nan; octave> B=[1,0,2;0,3,1]; octave> octave> (y*B)' ans = -2 NaN 0 1 2 12 15 18 NaN 24 0 NaN 6 NaN 12 octave> B'*y' ans = -2 NaN 0 NaN 2 12 NaN 18 NaN 24 0 NaN 6 NaN 12 The same behaviour is observed in 2.1.40 Is this a bug or an undocumented feature? A. ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html ------------------------------------------------------------- ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html -------------------------------------------------------------