Python SciPy – ndimage.map_coordinates()函数

此函数用于通过插值将给定数组映射到新坐标。坐标数组用于为输出中的每个点查找输入中的相应坐标。

Syntax: scipy.ndimage.map_coordinates(input, coordinates, output=None, order=3,cval=0.0, prefilter=True)

Parameters

• input:  which is of array_like – The input array.
• coordinates: which is of array_like- The coordinates at which input is evaluated.
• output:  which is an array – The array in which to place the output.
• order:  which is of int, – it is optional,The order of the spline interpolation,
• cval: it is a  scalar,-  it is optional,The  Value to fill past edges of input if mode is ‘constant’. Default is 0.0.
• prefilter: it is of boolean type, it is optional. it is used to determine if the input array is prefiltered with spline_filter before interpolation.

Returns: map_coordinates: ndarray

示例 1：

Python3

# importing numpy package for
# creating arrays
import numpy as np
 
# importing scipy
from scipy import ndimage
 
# creating an array from 0 to 15 values
a = np.arrange(16.).reshape((4, 4))
 
# finding coordinates
ndimage.map_coordinates(a, [[0.3, 1], [0.5, 1]], order=1)

输出：

array([1.7, 5. ])

示例 2：

蟒蛇3

# importing numpy package for
# creating arrays
import numpy as np
 
# importing scipy
from scipy import ndimage
 
a = np.arrange(25.).reshape((5, 5))
 
vals = [[0.3, 1], [0.5, 1]]
 
# calculating mode
print(ndimage.map_coordinates(a, vals, order=1, mode='nearest'))
print(ndimage.map_coordinates(a, vals, order=1, cval=0, output=bool))
print(ndimage.map_coordinates(a, vals, order=1))

输出：

[2. 6.]
[ True  True]
[2. 6.]