I followed the "waveform generator with Due" tutorial and found a minor typo,
sample = constrain(t_sample, 0, oneHzSample);
sample = constrain(sample, 0, oneHzSample);
The code compiled correctly and I was able to generate sine, square and saw-tooth waveform, the signal measured about 2.32 Vp-p
and a dc component about 0.5 V, since the signal is generated from DAC I should be able to change the amplitude of the signal, can someone show me where to find the information to do this.