How to create a sine wave with linear increasing amplitude transition

Hello everybody,

I would like to create a sine wave with linear increasing amplitude (Amp1 to Amp2), characteristics mentioned above:

Total duration: 9sec

Amplitude1: 0.3

Transition start time: 4th sec

Transition duration: 300ms

Amplitude2: 0.6

Thnx :)

Answer 1

[Russel Burgess]

One way:

t = linspace(0, 9, 10000); % s
f = 10; % Hz
A = 0.3.*(t<4) + (0.3 + (0.6 - 0.3)/0.3*(t-4)).*(t>=4 & t<4.3) + 0.6*(t>=4.3);
x = A.*sin(2.*pi.*f.*t);
plot(t, x);

[Sylvia Panagiotopoulou]

It works fine for me. Thank you very much Russel.