matplotlib 3D箭图,npy数据文件以给予3d矢量场

jexiocij 于 2023-05-01 发布在其他

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我想在Python中使用3D箭图绘制3D速度矢量场，来自3个数据文件（。npy），其给予x、y和z方向上的速度的u、v和w分量。这就是我到目前为止所做的，也显示了错误消息。我如何创建一个三维 Flutter 图从三个三维。npy数据文件？我还看了其他例子here和here。下面的代码改编自此处的二维 Flutter 图示例。

import numpy as np
from matplotlib import pyplot as plt
from matplotlib.pyplot import figure
from mpl_toolkits.mplot3d import proj3d

c1 = 1
nx, ny, nz = 284, 160, 160

x1 = range(nx)
y1 = range(ny)
z1 = range(nz)

U = np.load("u.npy") # 3d array file
V = np.load("v.npy") # 3d array file
W = np.load("w.npy") # 3d array file

X1, Y1, Z1 = np.meshgrid(x1, y1, z1)

fig = plt.figure(figsize=(10,10))
ax = fig.gca(projection='3d')
ax.set_title("pivot='mid'; every 10th arrow; units='velocity vector' time=" + str(c1))
Q = ax.quiver(X1[::10, ::10], Y1[::10, ::10], Z1[::10, ::10], U[::10, ::10],
    V[::10, ::10], W[::10, ::10], pivot='mid', units='inches')

#Not sure if it should be formatted as below:
#Q = ax.quiver(X1[::10, ::10, ::10], Y1[::10, ::10, ::10], Z1[::10, ::10, ::10], U[::10, ::10, ::10],
            #V[::10, ::10, ::10], W[::10, ::10, ::10], pivot='mid', units='inches')
qk = ax.quiverkey(Q, 0.9, 0.9, 5, r'$1 \frac{m}{s}$', labelpos='E', coordinates='figure') #possibly for 2D (X, Y) only.
ax.scatter(X1[::10, ::10], Y1[::10, ::10], Z1[::10, ::10], color='c', s=0)
plt.tight_layout()
plt.savefig('3D_video_velocity_' + str(c1) + '.png')

错误信息：

$ python3 test_3d_quiver_plot_1a.py 
Traceback (most recent call last):
  File "test_3d_quiver_plot_1a.py", line 69, in <module>
    Q = ax.quiver(X1[::10, ::10], Y1[::10, ::10], Z1[::10, ::10], U[::10, ::10],
  File "/home/brendan/.local/lib/python3.8/site-packages/mpl_toolkits/mplot3d/axes3d.py", line 2628, in quiver
    bcast = np.broadcast_arrays(*input_args, *masks)
  File "<__array_function__ internals>", line 5, in broadcast_arrays
  File "/home/brendan/.local/lib/python3.8/site-packages/numpy/lib/stride_tricks.py", line 264, in broadcast_arrays
    shape = _broadcast_shape(*args)
  File "/home/brendan/.local/lib/python3.8/site-packages/numpy/lib/stride_tricks.py", line 191, in _broadcast_shape
    b = np.broadcast(*args[:32])
ValueError: shape mismatch: objects cannot be broadcast to a single shape

结果应该如下所示：

matplotlib

来源：https://stackoverflow.com/questions/72207457/3d-quiver-plot-from-npy-data-files-to-give-a-3d-vector-field

2条答案

按热度按时间

bnl4lu3b1#

基于上述评论，要创建3D Flutter 图，X1, Y1, Z1, U, V, W必须具有相同的形状。
尝试修改以下代码行：

import numpy as np
nx, ny, nz = 160, 284, 160

x1 = range(nx)
y1 = range(ny)
z1 = range(nz)

X1, Y1, Z1 = np.meshgrid(x1, y1, z1)

请注意，我将nx, ny, nz = 284, 160, 160更改为nx, ny, nz = 160, 284, 160。这将给予X1, Y1, Z1提供正确的形状。

赞(0）回复(0）举报 2023-05-01

mfuanj7w2#

我发现下面的代码从3个数据文件中生成了一个3D振动图（3D阵列中。npy文件）。代码改编自@tacaswell。

from mpl_toolkits.mplot3d import axes3d
import matplotlib.pyplot as plt
import numpy as np

nx, ny, nz = 160, 284, 160

x1 = range(nx)
y1 = range(ny)
z1 = range(nz)

u = np.load("u.npy")
v = np.load("v.npy")
w = np.load("w.npy")

fig = plt.figure(figsize=(10,10))
ax = fig.gca(projection='3d')

x, y, z = np.meshgrid(x1, y1, z1)

# 3d quiver plot for every 5th data point
ax.quiver(x[::5, ::5], y[::5, ::5], z[::5, ::5], u[::5, ::5], 
    v[::5, ::5], w[::5, ::5], length=0.1, color = 'red', lw=2)

plt.show()

生成的3d箭图显示在这里（我还没有解决如何使箭头更大）：x1c 0d1x

赞(0）回复(0）举报 2023-05-01

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matplotlib 3D箭图,npy数据文件以给予3d矢量场

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