Evaluate a chirp signal at time t. A chirp signal is a frequency swept cosine wave.
y = chirp(t) y = chirp(t,f0) y = chirp(t,f0,t1) y = chirp(t,f0,t1,f1) y = chirp(t,f0,t1,f1,form) y = chirp(t,f0,t1,f1,form,phase)
vector of times to evaluate the chirp signal
frequency at time t=0 [0 Hz]
time t1 [1 sec]
frequency at time t=t1 [100 Hz]
shape of frequency sweep; 'linear' : f(t) = (f1-f0)*(t/t1) + f0, , 'quadratic': f(t) = (f1-f0)*(t/t1)^2 + f0, 'logarithmic': f(t) = (f1-f0)^(t/t1) + f0
phase shift at t=0
If you want a different sweep shape f(t), use the following: y = cos(2*%pi*integral(f(t)) + 2*%pi*f0*t + phase);
tfrsp(chirp([0:0.001:5])',1:5001,128,'plot'); // linear, 0-100Hz in 1 sec tfrsp(chirp([-2:0.001:15], 400, 10, 100, 'quadratic')',1:5001,128,'plot'); plot(chirp([0:1/8000:5], 200, 2, 500, "logarithmic")); // Shows linear sweep of 100 Hz/sec starting at zero for 5 sec // since the sample rate is 1000 Hz, this should be a diagonal // from bottom left to top right. tfrsp(chirp([0:0.001:5])',1:5001,128,'plot'); // linear, 0-100Hz in 1 sec // Shows a quadratic chirp of 400 Hz at t=0 and 100 Hz at t=10 // Time goes from -2 to 15 seconds. stacksize('max'); tfrsp(chirp([-2:0.001:15], 400, 10, 100, 'quadratic')',1:17001,128,'plot'); // Shows a logarithmic chirp of 200 Hz at t=0 and 500 Hz at t=2 // Time goes from 0 to 5 seconds at 8000 Hz. stacksize('max'); tfrsp(chirp([0:1/8000:5], 200, 2, 500, "logarithmic")',1:40001,128,'plot'); | ![]() | ![]() |