python - 从命令行绘制输入文件的数据

Question

我得到了一个名为“density_air.dat”的数据文件，我需要从每一列中获取数据并将它们放入自己的列表中(即 tList 将保存以“-10”和密度开头的列中的值将在以“1.341”开头的列中保存值。然后需要绘制列表。我在使用此数据填充列表时遇到问题...有任何帮助吗？

from scitools.std import *
import sys
import pylab as pl

inFile = sys.argv[-1]

f = open(inFile, 'r')

for x in range(4):
    f.readline()

tList = []
density = []

for line in f:
    words = line.split()
    for x in words:
        tList.append(words[x])
        density.append(words[x])

f.close()

plot(tList, density)

数据文件是:

# Density of air at different temperatures, at 1 atm pressure
# Column 1: temperature in Celsius degrees
# Column 2: density in kg/m^3 

-10     1.341
-5     1.316
 0     1.293
 5     1.269
10     1.247
15     1.225
20     1.204
25     1.184
30     1.164
# Source: Wikipedia (keyword Density)    

Answer 1

有一个名为 loadtxt 的 numpy 函数，它将 ascii 文件加载到 numpy 数组中:

import numpy as np
import matplotlib.pylab as plt
import sys

inFile = sys.argv[-1]
temperature, density = np.loadtxt(inFile,unpack=True)
plt.plot(temperature, density,'ko')
plt.show()