#
# Fourier Synthesis
#
sub fourier {
    my ($s1,@spectrum) = @_;
    my $coef;
 
    foreach $coef (@spectrum) {
        my @fpa = split /_/, $coef;      # get frequency,phase and amplitude
        &osc::sinus($s1,$fpa[0],$fpa[1],$fpa[2],1);
    }
}