def triangle_example(freq):
"""Makes a figure showing a triangle wave.
freq: frequency in Hz
"""
framerate = 10000
signal = thinkdsp.TriangleSignal(freq)
duration = signal.period * 3
segment = signal.make_wave(duration, framerate=framerate)
segment.plot()
thinkplot.save(root='triangle-%d-1' % freq,
xlabel='Time (s)',
axis=[0, duration, -1.05, 1.05])
wave = signal.make_wave(duration=0.5, framerate=framerate)
spectrum = wave.make_spectrum()
thinkplot.preplot(cols=2)
spectrum.plot()
thinkplot.config(xlabel='Frequency (Hz)', ylabel='Amplitude')
thinkplot.subplot(2)
spectrum.plot()
thinkplot.config(ylim=[0, 500], xlabel='Frequency (Hz)')
thinkplot.save(root='triangle-%d-2' % freq)
def dct_plot():
signal = thinkdsp.TriangleSignal(freq=400)
wave = signal.make_wave(duration=1.0, framerate=10000)
dct = wave.make_dct()
dct.plot()
thinkplot.config(xlabel='Frequency (Hz)', ylabel='DCT')
thinkplot.save(root='dct1', formats=['pdf', 'eps'])
def waveform(freq, btn_input):
if btn_input == 1:
signal = thinkdsp.SinSignal(freq)
if btn_input == 2:
signal = thinkdsp.SquareSignal(freq)
if btn_input == 3:
signal = thinkdsp.TriangleSignal(freq)
wave = signal.make_wave(framerate=samplingFreq)
return wave
def triangle_example(freq):
framerate = 10000
signal = thinkdsp.TriangleSignal(freq)
duration = signal.period*3
segment = signal.make_wave(duration, framerate=framerate)
segment.plot()
thinkplot.save(root='triangle-%d-1' % freq,
xlabel='time (s)',
axis=[0, duration, -1.05, 1.05])
wave = signal.make_wave(duration=0.5, framerate=framerate)
spectrum = wave.make_spectrum()
spectrum.plot()
thinkplot.save(root='triangle-%d-2' % freq,
xlabel='frequency (Hz)',
ylabel='amplitude')
import thinkdsp import matplotlib.pyplot as plt signal_tri = thinkdsp.TriangleSignal(200) #产生一个200Hz的三角波 plt.subplot(211) signal_tri.plot() wave = signal_tri.make_wave(duration=0.5, framerate=10000) spectrum = wave.make_spectrum() plt.subplot(212) spectrum.plot() plt.show()
from thinkdsp import Sinusoid
from thinkdsp import normalize,unbias
from thinkdsp import SquareSignal
from thinkdsp import TriangleSignal
from thinkdsp import decorate
import matplotlib.pyplot as plt
import numpy as np
plt.rcParams['font.sans-serif']=['SimHei']
plt.rcParams['axes.unicode_minus']=False
#三角波
class TriangleSignal(Sinusoid):
def evaluate(self,ts):
cycles = self.freq*ts+ self.offset/PI2
frac,_=np.modf(cycles)
ys=np.abs(frac-0.5)
ys=normalize(unbias(ys),self.amp)
return ys
signal1= thinkdsp.TriangleSignal(440).make_wave(duration = 0.01)
signal1.plot()
spectrum = signal1.make_spectrum()
print(spectrum.hs[0])
spectrum.hs[0]=100
spectrum.make_wave().plot(color='green')
plt.show()
# plt.show()
2 - 5
def filter_spectrum(spectrum):
"""Divides the spectrum through by the fs.
spectrum: Spectrum object
"""
# avoid division by 0
spectrum.hs[1:] /= spectrum.fs[1:]
spectrum.hs[0] = 0
wave = thinkdsp.TriangleSignal(freq=440).make_wave(duration=0.5)
wave.make_audio()
wave.plot()
plt.show()
spectrum = wave.make_spectrum()
spectrum.plot()
plt.show()
spectrum.plot(high=10000, color='red')
filter_spectrum(spectrum)
spectrum.scale(440)
spectrum.plot(high=10000, color='blue')
decorate(xlabel='Frequency (Hz)')
plt.show()
filtered = spectrum.make_wave()
def get_triangle_wave(freq, offset, duration=0.1, framerate=40000):
signal = thinkdsp.TriangleSignal(freq=freq, amp=1.0, offset=offset)
wave = signal.make_wave(duration=duration, start=0, framerate=framerate)
return wave.ys
import thinkdsp
import matplotlib.pyplot as plt
import numpy as np
from scipy import signal
from thinkdsp import TriangleSignal
from thinkdsp import decorate
plt.rcParams['font.sans-serif'] = ['SimHei'] #图表上可以显示中文
plt.rcParams['axes.unicode_minus'] = False #图表上可以显示负号
signal = thinkdsp.TriangleSignal(440)
wave = signal.make_wave(duration=0.5, framerate=10000)
#period=signal.period
segment = wave.segment(start=0, duration=0.01)
plt.subplot(1, 2, 1)
plt.title('440HZ三角波')
segment.plot()
spectrum = wave.make_spectrum()
plt.subplot(1, 2, 2)
plt.title('频谱')
spectrum.plot()
print(spectrum.hs[0])
plt.show()
import thinkdsp
import matplotlib.pyplot as plt
import numpy as np
from scipy import signal
plt.rcParams['font.sans-serif'] = ['SimHei'] #图表上可以显示中文
plt.rcParams['axes.unicode_minus'] = False #图表上可以显示负号
signal = thinkdsp.TriangleSignal(200) #200HZ的三角波
wave = signal.make_wave(duration=0.5, framerate=10000) #长度0.5，每秒10000次
period = signal.period
segment = wave.segment(start=0, duration=period * 3)
plt.subplot(2, 2, 1)
plt.title('200HZ三角波')
segment.plot()
spectrum = wave.make_spectrum()
plt.subplot(2, 2, 2)
plt.title('三角波频谱')
spectrum.plot()
#锯齿波
signal1 = thinkdsp.SawtoothSignal(200)
wave = signal1.make_wave(duration=0.5, framerate=10000)
period = signal1.period
segment = wave.segment(start=0, duration=period * 3)
plt.subplot(2, 2, 3)
plt.title('200HZ锯齿波')
segment.plot()
spectrum = wave.make_spectrum()
plt.subplot(2, 2, 4)
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Thu Aug 2 17:38:29 2018
@author: MikeNagler
"""
import thinkdsp
from thinkdsp import Signal, Wave, Spectrum
tri_sig = thinkdsp.TriangleSignal(freq=440)
tri_wave = tri_sig.make_wave(duration=0.01, start=1, framerate=11025)
tri_wave.plot()
tri_spec = tri_wave.make_spectrum()
tri_spec.plot()
print(tri_spec.hs[0])
tri_wave.write('temp.wav')
thinkdsp.play_wave('temp.wav', 'afplay')
tri_spec.hs[0] = 100
tri_spec.plot()
tri_wave2 = tri_spec.make_wave()
tri_wave2.plot()
tri_wave2.write(filename='temp2.wav')
thinkdsp.play_wave('temp2.wav', 'afplay')
plt.rcParams['font.sans-serif'] = ['SimHei']
plt.rcParams['axes.unicode_minus'] = False
signal1 = thinkdsp.SawtoothSignal(200)
plt.subplot(3, 2, 1)
plt.ylabel('200Hz锯齿波')
plt.title('波形')
signal1.plot()
sawtooth = SawtoothSignal().make_wave(duration=0.5, framerate=10000)
plt.subplot(3, 2, 2)
plt.title('频谱')
sawtooth.make_spectrum().plot()
signal2 = thinkdsp.TriangleSignal(200)
plt.subplot(3, 2, 3)
plt.ylabel('200Hz三角波')
signal2.plot()
wave2 = signal2.make_wave(duration=0.5, framerate=10000)
spectrum = wave2.make_spectrum()
plt.subplot(3, 2, 4)
spectrum.plot()
signal3 = thinkdsp.SquareSignal(200)
plt.subplot(3, 2, 5)
plt.ylabel('200Hz方波')
signal3.plot()
import thinkdsp import matplotlib.pyplot as plt from winsound import PlaySound import numpy as np signal_tri = thinkdsp.TriangleSignal(440) plt.subplot(411) signal_tri.plot() wave = signal_tri.make_wave(duration=0.01, framerate=10000) spectrum = wave.make_spectrum() plt.subplot(412) spectrum.plot() print(spectrum.hs[0]) print(np.angle(spectrum.hs[0])) print(np.abs(spectrum.hs[0])) spectrum.hs[0] = 100 print(spectrum.hs[0]) print(type(spectrum.hs[0])) wave = spectrum.make_wave() plt.subplot(413) wave.plot() spectrum = wave.make_spectrum() plt.subplot(414) spectrum.plot() plt.show()
def inverse_dct_iv(amps):
return dct_iv(amps) * 2
# In[20]:
amps = [0.6, 0.25, 0.1, 0.05]
ys = inverse_dct_iv(amps)
amps2 = dct_iv(ys)
print(max(abs(amps - amps2)))
# In[21]:
signal = thinkdsp.TriangleSignal(freq=400)
wave = signal.make_wave(duration=1.0, framerate=10000)
wave.make_audio()
# In[22]:
dct = wave.make_dct()
dct.plot()
thinkplot.config(xlabel='Frequency (Hz)', ylabel='DCT')
# In[23]:
wave2 = dct.make_wave()
# In[25]:
def af(spectrum):
number = np.size(spectrum.hs)
# print(number)
for i in range(number):
if i == 0:
spectrum.hs[0] = 0
else:
# print(spectrum.hs[i])
spectrum.hs[i] = spectrum.hs[i] / spectrum.fs[i]
# print(spectrum.fs[i])
# print(spectrum.hs[i])
return spectrum
signal_tri = thinkdsp.TriangleSignal(200) #生成一个200Hz的方波
plt.subplot(331)
signal_tri.plot()
wave = signal_tri.make_wave(duration=0.01, framerate=10000)
spectrum = wave.make_spectrum()
plt.subplot(334)
spectrum.plot()
s = af(spectrum)
plt.subplot(337)
s.plot()
signal_squ = thinkdsp.SquareSignal(200) #生成一个200Hz的三角波
plt.subplot(332)
signal_squ.plot()
wave = signal_squ.make_wave(duration=0.01, framerate=10000)
spectrum = wave.make_spectrum()
plt.subplot(335)