標籤:產生 cat 技術 info std 技術分享 RKE red style
#導包import numpy as np#匯入鳶尾花資料from sklearn.datasets import load_irisdata = load_iris()pental_len = data.data[:,2]print(pental_len)#計算尾花花瓣長度的最大值,平均值,中值,均方差print("最大值:",np.max(pental_len))print("平均值:",np.mean(pental_len))print("中值:",np.median(pental_len))print("均方差:",np.std(pental_len))#用np.random.normal()產生一個常態分佈的隨機數組,並顯示出來#常態分佈import numpy as npimport matplotlib.pyplot as pltmu = 2 #期望為2sigma = 3 #標準差為3num = 1000 #個數為10000rand_data = np.random.normal(mu, sigma, num)count, bins, ignored = plt.hist(rand_data, 30, normed=True)plt.plot(bins, 1/(sigma * np.sqrt(2 * np.pi)) *np.exp( - (bins - mu)**2 / (2 * sigma**2)), linewidth=2, color=‘r‘)plt.show()#np.random.randn()產生一個常態分佈的隨機數組,並顯示出來Data=np.random.randn(50)print(Data)#顯示鳶尾花花瓣長度的常態分佈圖,曲線圖,散佈圖#常態分佈圖import numpy as npimport matplotlib.pyplot as pltmu=np.mean(pental_len)sigma=np.std(pental_len)num=99999rand_data = np.random.normal(mu,sigma,num)count, bins, ignored = plt.hist(rand_data, 30, normed=True)plt.plot(bins, 1/(sigma * np.sqrt(2 * np.pi)) *np.exp( - (bins - mu)**2 / (2 * sigma**2)), linewidth=2, color=‘r‘)plt.show()#曲線圖#plt.plot(np.linspace(1,150,num=150),pental_len,‘c‘)plt.show()#散佈圖#plt.scatter(np.linspace(0,150,num=150),pental_len,alpha=0.5,marker=‘4‘)plt.show()
numpy統計分布顯示