def generate_chirp():
p = np.poly1d([1.4, 16])
t = np.linspace(0, 5, 5 * 48)
w = sweep_poly(t, p)
w = np.hanning(len(w)) * w
p = np.poly1d([-1.4, 30])
t0 = np.linspace(5, 10, 5 * 48)
t = np.append(t, t0)
w0 = sweep_poly(t0, p)
w0 = np.hanning(len(w0)) * w0
w = np.append(w, w0)
p = np.poly1d([1.4, 2])
t0 = np.linspace(10, 15, 5 * 48)
t = np.append(t, t0)
w0 = sweep_poly(t0, p)
w0 = np.hanning(len(w0)) * w0
w = np.append(w, w0)
p = np.poly1d([-1.4, 44])
t0 = np.linspace(15, 20, 5 * 48)
t = np.append(t, t0)
w0 = sweep_poly(t0, p)
w0 = np.hanning(len(w0)) * w0
w = np.append(w, w0)
w = w * 0.8
return w
def generate_chirp():
p = np.poly1d([7, 16])
t = np.linspace(0, 1, 1 * 48)
w = sweep_poly(t, p)
w = np.hanning(len(w)) * w
up_chirp = np.copy(w)
left_y = np.copy(w)
right_y = np.zeros(1 * 48)
p = np.poly1d([-7, 30])
t0 = np.linspace(1, 2, 1 * 48)
t = np.append(t, t0)
w0 = sweep_poly(t0, p)
w0 = np.hanning(len(w0)) * w0
w = np.append(w, w0)
down_chirp = np.copy(w0)
left_y = np.append(left_y, np.zeros(48))
right_y = np.append(right_y, w0)
return left_y, right_y, up_chirp, down_chirp
def make_sweep_poly(filename=None, fig_size=FIG_SIZE):
p = poly1d([0.05, -0.75, 2.5, 5.0])
t = np.linspace(0, t1, 5001)
w = sweep_poly(t, p)
figure(1, figsize=fig_size)
clf()
subplot(2, 1, 1)
plot(t, w)
tstr = "Sweep Poly, $f(t) = 0.05t^3 - 0.75t^2 + 2.5t + 5$"
title(tstr)
subplot(2, 1, 2)
plot(t, p(t), 'r')
grid(True)
ylabel('Frequency (Hz)')
xlabel('time (sec)')
if filename is None:
show()
else:
savefig(filename)
def make_sweep_poly(filename=None, fig_size=FIG_SIZE):
p = poly1d([0.05, -0.75, 2.5, 5.0])
t = np.linspace(0, t1, 5001)
w = sweep_poly(t, p)
figure(1, figsize=fig_size)
clf()
subplot(2, 1, 1)
plot(t, w)
tstr = "Sweep Poly, $f(t) = 0.05t^3 - 0.75t^2 + 2.5t + 5$"
title(tstr)
subplot(2, 1, 2)
plot(t, p(t), "r")
grid(True)
ylabel("Frequency (Hz)")
xlabel("time (sec)")
if filename is None:
show()
else:
savefig(filename)