function square = makesquare2(f,sf,amp,dur)
% function square = makesquare2(f,sf,amp,dur)
% Creates the timbre of a square wave by adding odd harmonics 
% with a magnitude proportional to the inverse of the harmonic number 
% ( a true square wave would contain an infinite number of odd harmonics)
% The square wave generator has a built in smart feature that does not allow 
% it to cause aliasing when adding the upper harmonics.
% Josh Arnold Decemebr 9,2004
% Modified by S. Scott Moor, Septemember 2005 
%
% Inputs: f = note frequency (Hz)
%         sf = sampling frequency (Hz)
%         amp = relative amplitude of the note (must be between 0 and 1)
%         dur = duration of note (seconds)
% Output: square = the wave series for the notes 

% hnum = number of the highest harmonic to add
% t = the time series for the note 
% num = the current number of the harmonic
% harmonic = the harmonic to be added to the series

% initialize values
hnum = 9;
t = 0:1/sf:dur;
square = sin(2*pi*f*t);
num = 3;                % start adding harmonics above the fundamental

%loop until all harmonics are created
while(num < hnum )

    if(num*f)<(sf/2)  % Anti-aliasing safeguard - throws out harmonics above the Nyquist frequency
        harmonic = ((1/num)*amp)*sin(2*pi*(f*num)*t);
    else
        harmonic = 0*amp*sin(2*pi*(f*num)*t);
    end

        square = square + harmonic;

    num = num +2;
end

%scale the wave's ampliude values to 0 -> amp (the provided amplitude) 
square = amp*(1/max(abs(square)))*square;