使用nditer对数组中的值进行排序

Question

我有两个文本文件，每个文件的像素强度来自一个图像。通过手动设置阈值将第一个文件转换为二进制图像：

import numpy as np
import matplotlib.pyplot as p

icp4 = np.loadtxt(icp4_img)
with np.nditer(icp4, op_flags=['readwrite']) as it:
    for x in it:
        if x[...] > 800:
            x[...] = 1
        else:
            x[...] = 0
p.imshow(icp4, interpolation='nearest', cmap='gray')
p.show()
print(icp4.shape)
>>>(45, 52)

对于第二个文件，我希望将像素值排序为两个列表，我将使用它们来绘制像素值的直方图，也就是说，如果像素在第一个数组中高于阈值，那么我希望将其排序到内部列表。

#sorting pixels for PTM channel
ptm = np.loadtxt(ptm_img)

inside = [] #list for pixel values that colocalize with icp4 signal
outside = [] #list for pixel values that do not colocalize with icp4 signal

with np.nditer(ptm, op_flags=['readonly']) as it:
    i=0
    for x in it:
        if icp4[i] > 0:
            inside.append(x[...])
        else:
            outside.append(x[...])
        i+=1
sys.exit()

当迭代数组ptm时，我不知道如何引用数组icp4中的相同位置。如果这是重复的问题，我很抱歉。

Answer 1

import numpy as np
import matplotlib.pyplot as p

icp4 = np.loadtxt(icp4_img)
ptm = np.loadtxt(ptm_img)

inside, outside = [], []

with np.nditer(icp4, op_flags=['readwrite']) as icp_it, np.nditer(ptm, op_flags=['readonly']) as ptm_it:
    for icp, ptm in zip(icp_it, ptm_it):
        if icp[...] > 800:
            icp[...] = 1
        else:
            icp[...] = 0
        if np.all(icp > 0):
            inside.append(ptm)
        else:
            outside.append(ptm)

p.imshow(icp4, interpolation='nearest', cmap='gray')
p.show()
print(icp4.shape)

sys.exit()