Tutorials and Topics - Peabody Computer Music

Tutorial 23Analysis:Viewing signal dataPeak amplitude: meter~The meter~ object periodically displays the peak amplitude it has received since the lastdisplay. At the same time it also sends the peak signal value out its outlet as a float. Theoutput value is always a positive number, even if the peak value was negative.meter~ displays the peak signal amplitude and sends it out as a floatmeter~ is useful for observing the peak amplitude of a signal (unlike number~, whichdisplays and sends out the instantaneous amplitude of the signal). Since meter~ isintended for audio signals, it expects to receive a signal in the range -1 to 1. If that range isexceeded, meter~ displays a red “clipping” LED as its maximum.• If you want to see the clipping display, increase the amplitude of the output signaluntil it exceeds 1. (Then return it to a desirable level.)The default interval of time between the display updates of meter~ is 250 milliseconds, butthe display interval can be altered with the interval message. A shorter display intervalmakes the LED display more accurate, while a longer interval gives you more time to readits visual and numerical output.• You can try out different display intervals by changing the number in the number boxmarked “Display Interval” in the lower left corner of the Patcher window.By the way, the display interval of a number~ object can be set in the same manner (as wellas via its Inspector window).Use a signal to generate Max messages: snapshot~The snapshot~ object sends out the current value of a signal, as does the right inlet ofnumber~. With snapshot~, though, you can turn the output on and off, or request outputof a single value by sending it a bang. When you send a non-zero number in the right inlet,snapshot~ uses that number as a millisecond time interval, and begins periodically189