matplotlib函数理解

cumsum()，通常用于计算一个数组各行的累加值，函数用法是B = cumsum(A,dim)，或B = cumsum(A)。

    def cumsum(self, axis=0, *args, **kwargs):
        """
        Cumulative sum of non-NA/null values.

        When performing the cumulative summation, any non-NA/null values will
        be skipped. The resulting SparseSeries will preserve the locations of
        NaN values, but the fill value will be `np.nan` regardless.

        Parameters
        ----------
        axis : {0}

        Returns
        -------
        cumsum : SparseSeries
        """

举例说明：

data数据，对盈利求和是37535

# A1的cumsum()是前1行的数据之和；A2的cumsum()是前2行的数据之和（9173+5729=14902）；……
data.cumsum()------
A1      9173
A2     14902
A3     19713
A4     23307
A5     26502
A6     29528
A7     31906
A8     33876
A9     35753
A10    37535

#Python程序段里的这条语句的意思是？
p = 1.0*data.cumsum()/data.sum()
# 1.0让数据浮点格式化
#

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