我正在开发一个项目，在该项目中，我从文本文件中读取值，该文件文件使用由空格分隔的两个值进行动态更新。将这些值放入列表中，然后绘制两个值，每个值都是y轴上的点，时间是x轴。在下面提供的第一组代码中，我可以接收值并绘制它们，然后将该图保存为png。但是，随着更多数据的出现，图表似乎不会更新时间值。但图表确实反映了值的变化。
# -*- coding: utf-8 -*-
"""
Created on Mon Jul 25 11:23:14 2016
@author: aruth3
"""
import matplotlib.pyplot as plt
import sys
import time
import datetime
class reader():
"""Reads in a comma seperated txt file and stores the two strings in two variables"""
def __init__(self, file_path):
"""Initialize Reader Class"""
self.file_path = file_path
# Read File store in f -- Change the file to your file path
def read_file(self):
"""Reads in opens file, then stores it into file_string as a string"""
f = open(self.file_path)
# Read f, stores string in x
self.file_string = f.read()
def split_string(self):
"""Splits file_string into two variables and then prints them"""
# Splits string into two variables
try:
self.val1, self.val2 = self.file_string.split(' ', 1)
except ValueError:
print('Must Have Two Values Seperated By a Space in the .txt!!')
sys.exit('Terminating Program -- Contact Austin')
#print(val1) # This is where you could store each into a column on the mysql server
#print(val2)
def getVal1(self):
return self.val1
def getVal2(self):
return self.val2
read = reader('testFile.txt')
run = True
tempList = []
humList = []
numList = [] # Represents 2 Secs
my_xticks = []
i = 0
while(run):
plt.ion()
read.read_file()
read.split_string()
tempList.append(read.getVal1())
humList.append(read.getVal2())
numList.append(i)
i = i + 1
my_xticks.append(datetime.datetime.now().strftime('%I:%M'))
plt.ylim(0,125)
plt.xticks(numList,my_xticks)
plt.locator_params(axis='x',nbins=4)
plt.plot(numList,tempList, 'r', numList, humList, 'k')
plt.savefig('plot.png')
time.sleep(10) # Runs every 2 seconds
testFile.txt有两个值100 90，可以动态更新并在图表中更改。但随着时间的推移，你会注意到（如果你运行代码）时间没有更新。
要解决时间不更新问题，我认为使用pop修改列表会允许第一个值离开，然后在循环时返回另一个值。就更新时间而言，这有效，但最终搞砸了图表： Link To Bad Graph Image
代码：
# -*- coding: utf-8 -*-
"""
Created on Tue Aug 2 09:42:16 2016
@author: aruth3
"""
# -*- coding: utf-8 -*-
"""
Created on Mon Jul 25 11:23:14 2016
@author:
"""
import matplotlib.pyplot as plt
import sys
import time
import datetime
class reader():
"""Reads in a comma seperated txt file and stores the two strings in two variables"""
def __init__(self, file_path):
"""Initialize Reader Class"""
self.file_path = file_path
# Read File store in f -- Change the file to your file path
def read_file(self):
"""Reads in opens file, then stores it into file_string as a string"""
f = open(self.file_path)
# Read f, stores string in x
self.file_string = f.read()
def split_string(self):
"""Splits file_string into two variables and then prints them"""
# Splits string into two variables
try:
self.val1, self.val2 = self.file_string.split(' ', 1)
except ValueError:
print('Must Have Two Values Seperated By a Space in the .txt!!')
sys.exit('Terminating Program -- Contact')
#print(val1) # This is where you could store each into a column on the mysql server
#print(val2)
def getVal1(self):
return self.val1
def getVal2(self):
return self.val2
read = reader('testFile.txt')
run = True
tempList = []
humList = []
numList = [] # Represents 2 Secs
my_xticks = []
i = 0
n = 0 # DEBUG
while(run):
plt.ion()
read.read_file()
read.split_string()
if n == 4:
my_xticks.pop(0)
tempList.pop(0)
humList.pop(0)
numList = [0,1,2]
i = 3
n = 3
tempList.append(read.getVal1())
humList.append(read.getVal2())
numList.append(i)
i = i + 1
my_xticks.append(datetime.datetime.now().strftime('%I:%M:%S')) # Added seconds for debug
plt.ylim(0,125)
plt.xticks(numList,my_xticks)
plt.locator_params(axis='x',nbins=4)
plt.plot(numList,tempList, 'r', numList, humList, 'k')
plt.savefig('plot.png')
time.sleep(10) # Runs every 2 seconds
n = n + 1
print(n) # DEBUG
print(numList)# DEBUG
print('-------')# DEBUG
print(my_xticks)# DEBUG
print('-------')# DEBUG
print(tempList)# DEBUG
print('-------')# DEBUG
print(humList)# DEBUG
所以我的问题是如何创建一个图表，当新值出现时，它会激活列表中的第一个值，从而更新时间，但是也可以提供精确的数据图表而不会出现故障？
列表中的弹出似乎是一个好主意，但我不确定为什么它会弄乱图表？
谢谢！
答案 0 :(得分：0)
这个问题在https://codereview.stackexchange.com/
可能更合适伪代码
plotData = []
for (1 to desired size)
plotData[i] = 0
while data
update time
plotData.push(data with time)
plotData.popTop(oldest data)
Draw plotData
end while