如何将数据从Meshgrid格式转换为数组,反之亦然:Python

时间:2019-04-12 22:18:19

标签: python arrays numpy

我有一个数据集data = f(x,y)。数据以网格格式提供。我想将其转换为数组,以使每一行都以[x,y,data]格式排序。另外,该怎么做?

import numpy as np

x = np.arange(-5, 5, 0.1)
y = np.arange(-4, 4, 0.1)
xx, yy = np.meshgrid(x, y)
data = np.sin(xx**2 + yy**2) / (xx**2 + yy**2)

print(data)  #Now it is in meshgrid format

2 个答案:

答案 0 :(得分:0)

您可以使用以下方法重塑数据:

1。网格格式

import numpy as np

x = np.arange(-5, 5, 2)
y = np.arange(-4, 4, 2)
xx, yy = np.meshgrid(x, y)
data = np.sin(xx**2 + yy**2) / (xx**2 + yy**2)

print(data)  # In meshgrid format

输出:

[[-0.00386885 -0.00529407 -0.05655279 -0.05655279 -0.00529407]
 [-0.02288393  0.03232054 -0.19178485 -0.19178485  0.03232054]
 [-0.00529407  0.04579094  0.84147098  0.84147098  0.04579094]
 [-0.02288393  0.03232054 -0.19178485 -0.19178485  0.03232054]]

2。列格式:

z = len(x)*len(y)
a = np.reshape(xx, z)
b = np.reshape(yy, z)
c = np.reshape(data, z)

new = np.c_[a, b, c]

print(new) # In an array ordered like [x, y, data]

输出:

[[-5.00000000e+00 -4.00000000e+00 -3.86884558e-03]
 [-3.00000000e+00 -4.00000000e+00 -5.29407000e-03]
 [-1.00000000e+00 -4.00000000e+00 -5.65527936e-02]
 [ 1.00000000e+00 -4.00000000e+00 -5.65527936e-02]
 [ 3.00000000e+00 -4.00000000e+00 -5.29407000e-03]
 [-5.00000000e+00 -2.00000000e+00 -2.28839270e-02]
 [-3.00000000e+00 -2.00000000e+00  3.23205413e-02]
 [-1.00000000e+00 -2.00000000e+00 -1.91784855e-01]
 [ 1.00000000e+00 -2.00000000e+00 -1.91784855e-01]
 [ 3.00000000e+00 -2.00000000e+00  3.23205413e-02]
 [-5.00000000e+00  0.00000000e+00 -5.29407000e-03]
 [-3.00000000e+00  0.00000000e+00  4.57909428e-02]
 [-1.00000000e+00  0.00000000e+00  8.41470985e-01]
 [ 1.00000000e+00  0.00000000e+00  8.41470985e-01]
 [ 3.00000000e+00  0.00000000e+00  4.57909428e-02]
 [-5.00000000e+00  2.00000000e+00 -2.28839270e-02]
 [-3.00000000e+00  2.00000000e+00  3.23205413e-02]
 [-1.00000000e+00  2.00000000e+00 -1.91784855e-01]
 [ 1.00000000e+00  2.00000000e+00 -1.91784855e-01]
 [ 3.00000000e+00  2.00000000e+00  3.23205413e-02]]

答案 1 :(得分:0)

您可以使用以下两个表达式:

# Convert from mesh to rows:
row_format = np.stack([z.ravel() for z in (xx, yy, data)], axis=1)

# Convert from rows to mesh:
xx, yy, data = np.swapaxes(row_format, 0, 1).reshape(3, len(y), len(x))