如何在numpy数组中找到最近的值?例子:
np.find_nearest(array, value)
如何在numpy数组中找到最近的值?例子:
np.find_nearest(array, value)
当前回答
这是在向量数组中找到最近向量的扩展。
import numpy as np
def find_nearest_vector(array, value):
idx = np.array([np.linalg.norm(x+y) for (x,y) in array-value]).argmin()
return array[idx]
A = np.random.random((10,2))*100
""" A = array([[ 34.19762933, 43.14534123],
[ 48.79558706, 47.79243283],
[ 38.42774411, 84.87155478],
[ 63.64371943, 50.7722317 ],
[ 73.56362857, 27.87895698],
[ 96.67790593, 77.76150486],
[ 68.86202147, 21.38735169],
[ 5.21796467, 59.17051276],
[ 82.92389467, 99.90387851],
[ 6.76626539, 30.50661753]])"""
pt = [6, 30]
print find_nearest_vector(A,pt)
# array([ 6.76626539, 30.50661753])
其他回答
稍微修改一下,上面的答案适用于任意维度的数组(1d, 2d, 3d,…):
def find_nearest(a, a0):
"Element in nd array `a` closest to the scalar value `a0`"
idx = np.abs(a - a0).argmin()
return a.flat[idx]
或者,写成一行:
a.flat[np.abs(a - a0).argmin()]
import numpy as np
def find_nearest(array, value):
array = np.array(array)
z=np.abs(array-value)
y= np.where(z == z.min())
m=np.array(y)
x=m[0,0]
y=m[1,0]
near_value=array[x,y]
return near_value
array =np.array([[60,200,30],[3,30,50],[20,1,-50],[20,-500,11]])
print(array)
value = 0
print(find_nearest(array, value))
对于2d数组,要确定最近元素的i, j位置:
import numpy as np
def find_nearest(a, a0):
idx = (np.abs(a - a0)).argmin()
w = a.shape[1]
i = idx // w
j = idx - i * w
return a[i,j], i, j
对于那些搜索多个最接近的,修改接受的答案:
import numpy as np
def find_nearest(array, value, k):
array = np.asarray(array)
idx = np.argsort(abs(array - value))[:k]
return array[idx]
看到的: https://stackoverflow.com/a/66937734/11671779
import numpy as np
def find_nearest(array, value):
array = np.asarray(array)
idx = (np.abs(array - value)).argmin()
return array[idx]
使用示例:
array = np.random.random(10)
print(array)
# [ 0.21069679 0.61290182 0.63425412 0.84635244 0.91599191 0.00213826
# 0.17104965 0.56874386 0.57319379 0.28719469]
print(find_nearest(array, value=0.5))
# 0.568743859261