Re: Using Play command and polynomial tia sal2

*To*: mathgroup at smc.vnet.net*Subject*: [mg97020] Re: Using Play command and polynomial tia sal2*From*: David Bailey <dave at removedbailey.co.uk>*Date*: Mon, 2 Mar 2009 05:22:35 -0500 (EST)*References*: <godm5p$48c$1@smc.vnet.net>

ratulloch at gmail.com wrote: > Greetings All > > I know the play command uses sin, cos, etc. But I would like to use > the Play command to listen to a polynomial. Example below of > polynomial > > Plot[Piecewise[{{4*x^2 - 4*x, 0 <= x <= 1}, {-2*x^2 + 8*x - 6 > , 1 = x < 3}}], {x, 0, 3}] > > I replace the Plot command with Play > Play[Piecewise[{{4*x^2 - 4*x, 0 <= x <= 1}, {-2*x^2 + 8*x - 6 > , 1 = x < 3}}], {x, 0, 3}] > > but mathematica 6 just comes back with errors and > just says running.. > > I think it's syntax but I haven't found an example of using the Play > command and Piecewise. Should I be doing this another way? > > tia sal2 > You had used = instead of == in one of the tests inside Piecewise. Curiously, this did not cause an error using Plot. Here is a corrected version: Play[Piecewise[{{4*x^2 - 4*x, 0 <= x <= 1}, {-2*x^2 + 8*x - 6, 1 == x < 3}}], {x, 0, 3}] Note that = means assignment, and therefore 1=x doesn't make sense - which is what the message was trying to tell you - whereas == is a comparison. However, I am not sure I would pay to attend a concert in which the result was playing :) I think the result would sound more interesting if instead of playing f[x], you played Sin[2 Pi f[x] x] with f scaled into the range of (say) 200-1000. The pitch of the resultant sound would represent the value of f. David Bailey http://www.dbaileyconsultancy.co.uk