summing signals + exponential curves


    Dec 11 2010 | 10:53 am
    Hi all.
    Is there a MSP version of expr? I need to sum about 6 signals together.
    Also, what is the best way to convert a midi stream (0-127) to an exponential curve to control a meter such as a volume slider?
    thanks

    • Dec 11 2010 | 11:06 am
      I'm sure I recall seeing a thread related to your first question; search for expr + msp, or expr + signal.
      As for the second, I found this use of [expr], but cannot recall the author:
    • Dec 11 2010 | 2:09 pm
      That was me I think. In this case something like the following patch might be easier though. Change the [pow] argument and mess with the slider to hear the effects.
    • Dec 11 2010 | 4:29 pm
      the volume slider is as linear as midi, no need to scale.
    • Dec 11 2010 | 6:14 pm
      Here's something much like Luke's solution, but using the decibel scale.
    • Dec 12 2010 | 10:47 pm
      You could also take a look at the jcom.map and jcom.dataspace externals, part of Jamoma:
      www.jamoma.org
    • Dec 13 2010 | 2:04 am
      btw, about your first question, you can sum signals using any MSP object, just
      connect 6 signals to one inlet and thats it.
    • Dec 13 2010 | 11:34 am
      I recall that someone made an attempt at an [expr~] object in the very early days of MSP, but it was CPU-intensive and very crash-prone.
      There's nothing you can do with expr (or an expr~) that you can't do by patching together mathematical objects. Although this can be a bit of work with complex formulae, at least it works.
    • Dec 13 2010 | 11:51 am
      It might be the same one peter mentioned though; haven't used it myself