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Python:返回特定范围内的矩阵值,范围以元组形式给出(从,到)

[英]Python: Returning values of matrix that are in a specific range, range is given as a tuple(from, to)

学校问题:

定义一个 2 参数(输入)function,它将返回给定范围内元素的平均值。 范围以元组形式给出。

我必须编写 2 个函数:

1是使用循环;

二是使用操作。

def mygmean(array,tuple):   # Determines values inside and outside a specified range
    """
    Determines values inside and outside a specified range.
    """
    
    import numpy as np
    incluided = []
    excluded = []
    
    
    for k in range(0, array.shape[0]):
        for i in range(0, array.shape[1]):
            if array[k,i] < tuple[0] or array[k,i] > tuple[-1]:
                excluded.append(array[k,i])
                pass
            else:
                incluided.append(array[k,i])
    final_geomean = np.prod(incluided)**(1/len(incluided))
        
    print(array)
    print(incluided)
    print(excluded)
    print(final_geomean)
    return(final_geomean,excluded)

编辑:通过编写解决了第 1 部分:

def mygmean(array,t):   # Determines values inside and outside a specified range
    """
    Determines values inside and outside a specified range.
    """
    
    import numpy as np
    incluided = []
    excluded = []
    
    for k in range(0, array.shape[0]):
        for i in range(0, array.shape[1]):
            if array[k,i] < t[0] or array[k,i] > t[-1]:
                excluded.append(array[k,i])
                pass
            else:
                incluided.append(array[k,i])
    final_geomean = np.prod(incluided)**(1/len(incluided))

    return(final_geomean,excluded)

控制台输入:

mygmean(np.array([[2,4],[-9,3],[6,-2],[8,1],[12,8]]),(0,10)))

所需的 output:

(3.684369762785971, array([-9, -2, 12]))

矢量化(即非循环)版本将使用nympy.wherenumpy.nanmean

import numpy as np
def mygmean(array, t):
    return np.nanmean(np.where((array>=t[0]) & (array<t[1]), array, np.nan))

# example
a = np.array([[1,2,3], [4,5,6]])
mygmean(a, (2,5))
# 3.0

注意。 我假设这里包括下限和排除上限

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