np.sum(matrix ** 2, axis=1, keepdims=True):这个函数计算矩阵每一行元素的平方和。axis=1 参数指定了函数沿着矩阵的行方向(即水平方向)进行操作,keepdims=True 参数确保结果保持二维数组的形状,以便后续进行广播运算。 matrix / ...:这里使用了元素级的除法运算,将矩阵的每一行除以该行元素平方和的平方根,从...
n_miss = dataframe[na_columns].isnull.sum.sort_values(ascending=False)ratio = (dataframe[na_columns].isnull.sum / dataframe.shape[0] * 100).sort_values(ascending=False)missing_df = pd.concat([n_miss, np.round(ratio, 2)], axis=1, keys=['n_miss', 'ratio'])print(missing_df, end...
多点坐标的暴力穷举 | import numpy as np from itertools import permutations def compute_distance_matrix(points): """计算点之间的欧氏距离矩阵""" points = np.array(points) diff = points[:, np.newaxis, :] - points[np.newaxis, :, :] return np.sqrt((diff**2).sum(axis=2)) def calculate...
我打比赛的时候,为了生成一个新变量,用了groupby的apply,写了这么一句:ins['weight'] = ins[['SK_ID_PREV','DAYS_ENTRY_PAYMENT']].groupby('SK_ID_PREV').apply(lambda x: 1-abs(x)/x.sum.abs).iloc[:,1],1000万行的数据,足足算了十多分钟,等得我心力交瘁。 绘图 因为Excel画出来的图能够交互...
fill_value=1e+20)In[6]:a.mean()__array_wrap___array_finalize___array_wrap___array_finalize___array_finalize__Out[6]:masked_array(data=4.5,mask=False,fill_value=1e+20)In[7]:b.mean()Out[7]:4.5In[8]:a.sum()Out[8]:45.0In[9]:b.sum()Out[9]:45.0In[10]:np.ma.median(...
n_miss = dataframe[na_columns].isnull.sum.sort_values(ascending=False)ratio = (dataframe[na_columns].isnull.sum / dataframe.shape[0] * 100).sort_values(ascending=False)missing_df = pd.concat([n_miss, np.round(ratio, 2)], axis=1, keys=['n_miss', 'ratio'])print(missing_df, end...
atmosphere Article The Deep Physics Hidden within the Field Expressions of the Radiation Fields of Lightning Return Strokes Vernon Cooray 1,* and Gerald Cooray 2 1 Department of Engineering Sciences, Uppsala University, 751 21 Uppsala, Sweden 2 Department of Clinical Neuroscience, Karolinska University...