从Python中的电子表格列进行Contourf绘图

Question

我想从逗号分隔的文本文件的3列中绘制带有x，y，z的彩色轮廓图，但是每次尝试下面的代码时，我都会遇到ValueError：太多的值无法解包（预期3）错误。 如果能解决我将不胜感激。

我还想知道是否还有另一个（可能更好）的代码来绘制3个独立的列。

这是代码：

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib import cm
import numpy as np
import scipy.interpolate

N = 100000

long_col, lat_col, Bouguer_col = np.genfromtxt(r'data.txt', unpack=True)

xi = np.linspace(long_col.min(), long_col.max(), N)
yi = np.linspace(lat_col.min(), lat_col.max(), N)
zi = scipy.interpolate.griddata((long_col, lat_col), Bouguer_col, (xi[None,:], yi[:,None]), method='cubic')


fig = plt.figure()
plt.contourf(xi, yi, zi)
plt.xlabel("Long")
plt.ylabel("Lat")
plt.show()

这是“ data.txt”示例数据。

Lat, Long, Elev, ObsGrav, Anomalies
6.671482000000001022e+00,7.372505999999999560e+00,3.612977999999999952e+02,9.780274000000000233e+05,-1.484474523360840976e+02
6.093078000000000216e+00,7.480882000000001142e+00,1.599972999999999956e+02,9.780334000000000233e+05,-1.492942383352201432e+02
6.092045999999999850e+00,7.278669999999999973e+00,1.462445999999999913e+02,9.780663000000000466e+05,-1.190960417173337191e+02
6.402087429999999912e+00,7.393360939999999992e+00,5.237939999999999827e+02,9.780468000000000466e+05,-8.033459449396468699e+01
6.264082730000000154e+00,7.518244540000000420e+00,2.990849999999999795e+02,9.780529000000000233e+05,-1.114865156192099676e+02
6.092975000000000030e+00,7.482914000000000065e+00,1.416474000000000046e+02,9.780338000000000466e+05,-1.525697779102483764e+02
6.383570999999999884e+00,7.289616999999999791e+00,2.590403000000000020e+02,9.780963000000000466e+05,-8.300666170357726514e+01
6.318417000000000172e+00,7.557638000000000744e+00,1.672036999999999978e+02,9.780693000000000466e+05,-1.246774551668204367e+02
6.253779999999999895e+00,7.268805999999999656e+00,1.059429999999999978e+02,9.781026999999999534e+05,-9.986763240839354694e+01
6.384635000000000282e+00,7.291032000000000401e+00,2.615624000000000251e+02,9.780963000000000466e+05,-8.256190758384764194e+01

Answer 1

如果数据文件看起来完全像问题中的一样，则您首先有5列，您不能将它们解压缩为3个变量。
接下来，您有一个标题行，您不想成为数据的一部分。 标题行也由,<space>分隔，而数据由, 。分隔。

所以总共你需要

import numpy as np

a,b,c,d,e = np.genfromtxt("data.txt", unpack=True, delimiter=",", skip_header=1)