Cycling 74 » Topic: Imaginary input to pfft~? http://cycling74.com/forums/topic/imaginary-input-to-pfft/feed Wed, 19 Jun 2013 22:52:05 +0000 http://bbpress.org/?v=2.2.4 http://cycling74.com/forums/topic/imaginary-input-to-pfft/#post-64977 <![CDATA[Imaginary input to pfft~?]]> http://cycling74.com/forums/topic/imaginary-input-to-pfft/#post-64977 Mon, 29 Oct 2012 05:42:25 +0000 keytarhero I’m building a software-defined radio receiver in Max/MSP, but unfortunately I’m having some issues with its complex signal support. What I’m trying to do is create a waterfall plot that displays all frequencies from -22050 to +22050 Hz. I’ve run into a bit of a problem though – displaying a complex spectrogram requires real and imaginary inputs, and with a spectroscope~ this only works inside a pfft~. (Unfortunately, this also means there’s no way to display the spectroscope in the main patcher window, but that’s a whole other issue altogether.) While I could use a pfft~, the problem is that it only takes real inputs (unlike fft~, which has an optional imaginary input as well). I find this to be really odd, since the pfft~ has a full-spectrum flag and there’s no reason you would need a full-spectrum flag without complex inputs.

So anyway, I need to do one of 3 things: find a way of putting a complex input to pfft~, find a way for a complex spectroscope~ to work with fft~ (I’m assuming this doesn’t work because it needs fftinfo?), or find a different way to get a complex waterfall plot working (possibly with a 3rd-party object, or some sort of jitter thing?). I figure there must be some way to get a complex input into pfft~, but I can’t figure out how.

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