データを利用する数の変更

前提・実現したいこと

N＝200でデータを200個で設定しているがスペクトルの部分では100個のデータを扱ってグラフを表示させたい

発生している問題・エラーメッセージ

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-182-b26606588d01> in <module>
     23 plt.title('waveform'); plt.xlabel('time [s]'); plt.ylabel('amplitude')
     24 plt.subplot(4,1,2)
---> 25 plt.stem(frequency,A,markerfmt='None',use_line_collection=True)
     26 plt.title('spectrum'); plt.xlabel('freq [hz]'); plt.ylabel('gain')
     27 plt.subplot(4,1,3)

~\Anaconda3\lib\site-packages\matplotlib\pyplot.py in stem(linefmt, markerfmt, basefmt, bottom, label, use_line_collection, data, *args)
   2904         bottom=bottom, label=label,
   2905         use_line_collection=use_line_collection, **({"data": data} if
-> 2906         data is not None else {}))
   2907 
   2908 

~\Anaconda3\lib\site-packages\matplotlib\__init__.py in inner(ax, data, *args, **kwargs)
   1587     def inner(ax, *args, data=None, **kwargs):
   1588         if data is None:
-> 1589             return func(ax, *map(sanitize_sequence, args), **kwargs)
   1590 
   1591         bound = new_sig.bind(ax, *args, **kwargs)

~\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py in stem(self, linefmt, markerfmt, basefmt, bottom, label, use_line_collection, *args)
   2848 
   2849         markerline, = self.plot(x, y, color=markercolor, linestyle=markerstyle,
-> 2850                                 marker=markermarker, label="_nolegend_")
   2851 
   2852         baseline, = self.plot([np.min(x), np.max(x)], [bottom, bottom],

~\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py in plot(self, scalex, scaley, data, *args, **kwargs)
   1664         """
   1665         kwargs = cbook.normalize_kwargs(kwargs, mlines.Line2D._alias_map)
-> 1666         lines = [*self._get_lines(*args, data=data, **kwargs)]
   1667         for line in lines:
   1668             self.add_line(line)

~\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in __call__(self, *args, **kwargs)
    223                 this += args[0],
    224                 args = args[1:]
--> 225             yield from self._plot_args(this, kwargs)
    226 
    227     def get_next_color(self):

~\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in _plot_args(self, tup, kwargs)
    389             x, y = index_of(tup[-1])
    390 
--> 391         x, y = self._xy_from_xy(x, y)
    392 
    393         if self.command == 'plot':

~\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in _xy_from_xy(self, x, y)
    268         if x.shape[0] != y.shape[0]:
    269             raise ValueError("x and y must have same first dimension, but "
--> 270                              "have shapes {} and {}".format(x.shape, y.shape))
    271         if x.ndim > 2 or y.ndim > 2:
    272             raise ValueError("x and y can be no greater than 2-D, but have "

ValueError: x and y must have same first dimension, but have shapes (100,) and (200,)

該当のソースコード

python
1import numpy as np
2import matplotlib.pyplot as plt
3import sip
4
5N=200
6
7x, fs = sip.wavread("./sounds/dialtone2.wav")
8print("Sampling Rate = ", fs, "Hz")
9
10X=sip.dft(x[0:N])
11y=sip.idft(X)
12
13A=np.abs(X)
14AdB = 20*np.log10(A)
15k=np.arange(N/2)
16print(k)
17
18frequency = (k*fs)/N
19
20plt.figure(figsize=(10,10))
21plt.subplot(4,1,1)
22plt.plot(np.arange(N)/fs,x[0:N])
23plt.title('waveform'); plt.xlabel('time [s]'); plt.ylabel('amplitude')
24plt.subplot(4,1,2)
25plt.stem(frequency,A,markerfmt='None',use_line_collection=True)
26plt.title('spectrum'); plt.xlabel('freq [hz]'); plt.ylabel('gain')
27plt.subplot(4,1,3)
28plt.stem(frequency,AdB,markerfmt='None',use_line_collection=True)
29plt.title('spectrum'); plt.xlabel('freq [hz]'); plt.ylabel('gain [dB]')
30plt.subplot(4,1,4)
31plt.plot(np.arange(N)/fs,np.real(y))
32plt.title('waveform'); plt.xlabel('time [s]'); plt.ylabel('amplitude')
33
34plt.tight_layout()
35plt.show()