# Trying to play/export formula to audio file tia sal2

Discussion in 'Maple' started by sal2, Jun 13, 2006.

1. ### sal2Guest

Greetings All

I'm try to export/play this formula to a wave file I looked at the signal
generation example and didn't find a place to insert this formula to be
played.

animate(plot, [sin(x)+2*sin(2*x)+4*sin(4*x)+8*sin(8*x)+7*sin(7*x)+5*sin(5
*x), x = 0 .. t], t = 0 .. 2*Pi)

PS: I'm using maple 10.

tia sal2

sal2, Jun 13, 2006

2. ### Walter RobersonGuest

Ummm, what did you want the resulting signal to be?

What sampling frequency do you want to use?

The plot has a warped-triangle shape because your x runs only to t;
how did you want to convert that aspect into audio?

Your plot has a range of about +/- 22 rather than 0..1: what
scaling function do you want to use to normalize the data?

Walter Roberson, Jun 13, 2006

3. ### tempGuest

-cnrc.gc.ca (Walter Roberson) wrote in
Sorry I didn't know I was missing information. I was trying to replicate
this mathematica command
Play[Sin[x] + 2Sin[2x] + 4Sin[4x] + 8Sin[8x] + 7Sin[7x] + 5Sin[5x], {x,
0, 2Pi}];

I prefer to use maple because I like it alot better.

The formula I'm using is sin(x)+2*sin(2*x)+4*sin(4*x)+8*sin(8*x)+7*sin(7
*x)+5*sin(5*x);

16bit mono
44100
run for 5 sec

I just need a small example of how to use an equation to create an audio
file I'll be able to adjust it.

Tia

temp, Jun 13, 2006
4. ### Robert IsraelGuest

I think you want something like this:
A:= Create(duration=5.0);
G:= proc(freq,A)
local i,x,w;
w:= 2*Pi*freq/44100;
for i from 1 to 220500 do
x:= i*w;
A:= sin(x)+2*sin(2*x)+4*sin(4*x)+8*sin(8*x)
+7*sin(7*x)+5*sin(5*x);
end do;
Normalize(A)
end proc:
evalhf(G(440,A)):
Write("myfile.wav",Normalize(A)):

Robert Israel
Department of Mathematics http://www.math.ubc.ca/~israel
University of British Columbia Vancouver, BC, Canada

Robert Israel, Jun 13, 2006
5. ### Walter RobersonGuest

In that 5 seconds, do you want it to complete exactly 1 period?
You have t = 2*Pi as your maximum; if you were to use the
"natural" mapping of t as seconds, then the maximum would be about
6 1/4 seconds instead of 5 seconds. But the human ear is only
sensitive down to about 20 Hz, and none of your multipliers
gets as high as 20*5, so all you would be able to hear would
be the harmonics.

Walter Roberson, Jun 14, 2006