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From: Ivica Ico Bukvic [mailto:[email protected]] Sent: Tuesday, April 23, 2013 11:15 PM To: 'Charles Z Henry' Subject: RE: [PD] Negative input numbers for [pow] return 0 Yes, the proposed patch generates 0 when imaginary numbers are involved and issues warning on the console with ability to track the error. From: Charles Z Henry [mailto:[email protected]] Sent: Tuesday, April 23, 2013 10:39 PM To: Ivica Ico Bukvic Cc: pd-list; IOhannes m zmoelnig Subject: Re: [PD] Negative input numbers for [pow] return 0 Yep. It's damaging to have NaN's propagating around in Pd. [pow] having a single output means that you only want real values. The result is not a real number-I think the result should just be set to 0 (perhaps 1 depending on what the worst usage case is). Would it be better to have pow just output the real part of the complex number, generated from: (-1*base)^exp*e^(pi*exp*i) Which is (-1*base)^exp*cos(pi*exp) when base is a negative number this assumes the standard branch cut in complex analysis: -1=e^(pi*i) and not e^(3*pi*i) or any other Chuck On Apr 23, 2013 9:11 PM, "Ivica Ico Bukvic" <[email protected]> wrote: It may be a bit more complex since exponent values between -1 and 1 are the ones that generate imaginary numbers from negative values, with the exception of 0 which generates 1. Latest pd-l2ork patch tries to fix this. See: https://github.com/pd-l2ork/pd/commit/95d82d33d2580a00e32d725e0f5147d88cdaf3 70 > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of > IOhannes m zmoelnig > Sent: Tuesday, April 23, 2013 6:21 AM > To: [email protected] > Subject: Re: [PD] Negative input numbers for [pow] return 0 > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 2013-04-23 11:50, Joe White wrote: > > Out of curiosity, are the workarounds suggested more of a result of > > the difficulty of extending the Pd core rather than the > > implications that such a change might have? > > the implementation would be trivial (merely removing the safeguards > that currently clamp the value to 0) > > fgmasdr > IOhannes > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.12 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iEYEARECAAYFAlF2YIEACgkQkX2Xpv6ydvQyoQCgiC95SRoOKaOHu6qkmpX+kD8 > 0 > /ugAoJymAbmtt6qWkZM5rAlObyhdarRF > =KUIu > -----END PGP SIGNATURE----- > > _______________________________________________ > [email protected] mailing list > UNSUBSCRIBE and account-management -> > http://lists.puredata.info/listinfo/pd-list _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
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