Sine Wave Points

gistfile1.erl

%% @doc Generate a set of points representing a sine wave
%% given some parameters (position, points to generate, freqency, amplitude,
%% offset, sample rate).
%% @end
sine(X, N=0, Frequency, Amplitude, Offset, SampleRate)
        when is_integer(X), is_integer(N), is_float(Frequency),
        is_float(Amplitude), is_float(Offset), is_float(SampleRate)->
    [];
sine(X, N, Frequency, Amplitude, Offset, SampleRate)
        when is_integer(X), is_integer(N), is_float(Frequency),
        is_float(Amplitude), is_float(Offset), is_float(SampleRate) ->
    Y0 = math:sin(2*math:pi()*X*(Frequency/SampleRate)),
    Y1 = Amplitude*Y0,
    Y2 = round(Y1),
    Y3 = Y2 + Offset,
    [X, Y3 | sine(X+1, N-1, Frequency, Amplitude, Offset, SampleRate)].