Python數(shù)據(jù)分析基礎(chǔ)與應(yīng)用電子活頁(yè)3-29實(shí)現(xiàn)NumPy數(shù)組的統(tǒng)計(jì)計(jì)算

Python數(shù)據(jù)分析基礎(chǔ)與應(yīng)用模塊電子活頁(yè)3-29實(shí)現(xiàn)NumPy數(shù)組的統(tǒng)計(jì)計(jì)算【技能訓(xùn)練3-42】實(shí)現(xiàn)NumPy數(shù)組的統(tǒng)計(jì)計(jì)算【訓(xùn)練要求】在JupyterNotebook開(kāi)發(fā)環(huán)境中創(chuàng)建j3-42.ipynb，然后編寫(xiě)代碼實(shí)現(xiàn)NumPy數(shù)組的統(tǒng)計(jì)計(jì)算?！緦?shí)施過(guò)程】（1）計(jì)算NumPy數(shù)組元素沿指定軸的最小值與最大值代碼如下：importnumpyasnparray1=np.array([[3,7,5],[8,4,3],[2,4,9]])print(array1)#調(diào)用amin()函數(shù)print(np.amin(array1))#調(diào)用amin()函數(shù)，取axis=1print(np.amin(array1,1))#調(diào)用amax()函數(shù)print(np.amax(array1))#調(diào)用amax()函數(shù)，取axis=0print(np.amax(array1,axis=0))輸出結(jié)果：[[375][843][249]]2[332]9[879]（2）計(jì)算NumPy數(shù)組元素中最大值與最小值的差值代碼如下：importnumpyasnparray2=np.array([[3,7,5],[8,4,3],[2,4,9]])print("原數(shù)組：\n",array2)print(np.ptp(array2))print("沿著行方向：",np.ptp(array2,1))print("沿著列方向：",np.ptp(array2,0))輸出結(jié)果：原數(shù)組：[[375][843][249]]7沿著行方向：[457]沿著列方向：[636]（3）沿指定軸計(jì)算NumPy數(shù)組元素的百分位數(shù)代碼如下：importnumpyasnparray3=np.array([[2,10,20],[80,43,31],[22,43,10]])print("原數(shù)組array3：\n",array3)print("沿著axis=0計(jì)算百分位數(shù)",np.percentile(array3,10,0))print("沿著axis=1計(jì)算百分位數(shù)",np.percentile(array3,10,1))輸出結(jié)果：原數(shù)組array3：[[21020][804331][224310]]沿著axis=0計(jì)算百分位數(shù)[6.16.612.]沿著axis=1計(jì)算百分位數(shù)[3.633.412.4]（4）計(jì)算NumPy數(shù)組元素的中位數(shù)代碼如下：array4=np.array([[30,65,70],[80,95,10],[50,90,60]])#輸出數(shù)組array4print(array4)#調(diào)用median()函數(shù)print(np.median(array4))#axis=0print(np.median(array4,axis=0))#axis=1print(np.median(array4,axis=1))輸出結(jié)果：[[306570][809510][509060]]65.0[50.90.60.][65.80.60.]（5）沿指定的軸計(jì)算NumPy數(shù)組元素的算術(shù)平均值代碼如下：importnumpyasnparray5=np.array([[1,2,3],[3,4,5],[4,5,6]])print(array5)#調(diào)用mean()函數(shù)print(np.mean(array5))print('沿軸0調(diào)用mean()函數(shù)：')print(np.mean(array5,axis=0))print('沿軸1調(diào)用mean()函數(shù)：')print(np.mean(array5,axis=1))輸出結(jié)果：[[123][345][456]]3.6666666666666665沿軸0調(diào)用mean()函數(shù)：[2.666666673.666666674.66666667]沿軸1調(diào)用mean()函數(shù)：[2.4.5.]（6）使用average()函數(shù)計(jì)算NumPy數(shù)組元素的加權(quán)平均值代碼如下：importnumpyasnparray6=np.array([1,2,3,4])print(array6)#未指定權(quán)重調(diào)用average()函數(shù)print(np.average(array6))#若不指定權(quán)重相當(dāng)于對(duì)數(shù)組元素求算術(shù)平均值weight=np.array([4,3,2,1])#指定權(quán)重調(diào)用average()函數(shù)print(np.average(array6,weights=weight))#若returned為T(mén)rue，則返回加權(quán)平均值和權(quán)重之和print(np.average([1,2,3,4],weights=[4,3,2,1],returned=True))輸出結(jié)果：[1234]2.52.0(2.0,10.0)在多維數(shù)組中計(jì)算加權(quán)平均值時(shí)，還可以指定axis參數(shù)。代碼如下：importnumpyasnparray7=np.arange(6).reshape(3,2)print(array7)wt=np.array([3,5])print(np.average(array7,axis=1,weights=wt))print(np.average(array7,axis=1,weights=wt,returned=True))輸出結(jié)果：[[01][23][45]][0.6252.6254.625](array([0.625,2.625,4.625]),array([8.,8.,8.]))（7）使用var()函數(shù)計(jì)算NumPy數(shù)組元素的方差代碼如下：importnumpyasnp