[sdiy] Converting Sine to Triangle Wave?

[Tim Stinchcombe]

Glen,

> I'm looking for some sort of math formula to convert a sine 
> wave to a triangle wave. Does something like this exist?

If you are happy to also use the odd multiples of the frequency of your
sine/cosine wave, then the Fourier series gives it to you, i.e. the Fourier
series of

f(x)=|x|= x for 0<x<pi, or -x for -pi<x<0

is

pi/2-4/pi*(1/1^2*cosx+1/3^2*cos3x+1/5^2*cos5x+...)

(so says Schaum's Mathematical Handbook of Formulas and Tables)

Tim
__________________________________________________________
Tim Stinchcombe 

Cheltenham, Glos, UK
email: tim102 at tstinchcombe.freeserve.co.uk