function [out] = trifreq (secs, varargin)
%trifreq

samprate = 44100;  

if (evalin ('base', 'exist(''params'')'))
  params = evalin ('base', 'params');
  bpm = params.bpm;
  samprate = params.samprate;
end

freq = 440;
phase = 0;
if (nargin > 1)
  freq = varargin{1};
end

if (nargin > 2)
  phase = mod (varargin{2}, 1);
end

wlength = samprate / freq;
wphase = phase * wlength;

out = triwave (secs * samprate, wlength, wphase);