NumPy中满足条件的数组掩码
要掩盖满足条件的数组,请在Python NumPy中使用**numpy.ma.masked_where()**方法。将要掩盖的数组返回为在condition为True时被掩盖的数组。a或condition的任何掩盖值在输出中也会被掩盖。
condition参数设置掩码条件。当condition测试浮点值的相等性时,请考虑使用masked_values代替。copy参数,如果为True(默认值),则在结果中复制a。如果为False,则就地修改a并返回视图。
步骤
首先,导入所需的库:
import numpy as np import numpy.ma as ma
使用numpy.array()方法创建一个包含整数元素的数组:
arr = np.array([[71, 55, 91], [82, 33, 39], [73, 82, 51], [90, 45, 82]])
print("Array...
", arr)获取数组的类型:
print("
Array type...
", arr.dtype)
获取数组的维度:
print("
Array Dimensions...
",arr.ndim)获取数组的形状:
print("
Our Array Shape...
",arr.shape)
获取数组的元素个数:
print("
Number of Elements in the Array...
",arr.size)要掩盖满足条件的数组,请在Python NumPy中使用numpy.ma.masked_where()方法。这里,所有大于60的元素都将被掩盖:
print("
Result...
",np.ma.masked_where(arr > 60, arr))
示例
import numpy as np
import numpy.ma as ma
# Create an array with int elements using the numpy.array() method
arr = np.array([[71, 55, 91], [82, 33, 39], [73, 82, 51], [90, 45, 82]])
print("Array...
", arr)
# Get the type pf array
print("
Array type...
", arr.dtype)
# Get the dimensions of the Array
print("
Array Dimensions...
",arr.ndim)
# Get the shape of the Array
print("
Our Array Shape...
",arr.shape)
# Get the number of elements of the Array
print("
Number of Elements in the Array...
",arr.size)
# To mask an array where a condition is met, use the numpy.ma.masked_where() method in Python Numpy
# Here, all the elements above 60 will get masked
print("
Result...
",np.ma.masked_where(arr > 60, arr))输出
Array... [[71 55 91] [82 33 39] [73 82 51] [90 45 82]] Array type... int64 Array Dimensions... 2 Our Array Shape... (4, 3) Number of Elements in the Array... 12 Result... [[-- 55 --] [-- 33 39] [-- -- 51] [-- 45 --]]
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