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設定一頻率為1Hz的正弦波, 產生以此正弦波為目標,取樣率為1Hz, 10Hz, 20Hz 的離散訊號 Example Code

import scipy as sp
import matplotlib.pyplot as plt
def GenSin(x,Hz):
	return sp.sin(Hz*x*sp.pi*2)
N=[10,20,30] #sampling data points
fig, ax = plt.subplots( 4,1, sharey=True)
for i in N:
	dataX = sp.linspace(0, 2, i)
	dataY = GenSin(dataX,i)
	ax[N.index(i)].stem(dataX,dataY, use_line_collection=True)
	ax[N.index(i)].set_axis_off()
semiCountinue=sp.linspace(0, 2, 200)
ax[3].plot(semiCountinue, GenSin(semiCountinue,1))
plt.savefig("sampleing.jpg",dpi=200)
plt.show()

Note and Comments

import scipy as sp　讀入scipy函式庫並命名為sp
import matplotlib.pyplot as plt 讀入matplotlib.pyplot函式庫並命名為plt
def GenSin(x,Hz): 定義Sine函數, 兩個參數分別為x軸的數值與頻率
	return sp.sin(Hz*x*sp.pi*2)
N=[10,20,30] #sampling data points
fig, ax = plt.subplots( 4,1, sharey=True)
for i in N:
	dataX = sp.linspace(0, 2, i) #産生範圍由0到2,N個點的數列
	dataY = GenSin(dataX,i)　#已dataX為自變數,產生y軸數據
	ax[N.index(i)].stem(dataX,dataY, use_line_collection=True)　#畫枝幹圖
	ax[N.index(i)].set_axis_off()　#不畫出座標軸
semiCountinue=sp.linspace(0, 2, 200)
ax[3].plot(semiCountinue, GenSin(semiCountinue,1))　#畫出正弦波
plt.savefig("sampleing.jpg",dpi=200)
plt.show()

result

Waveform and sampleing rate