DrivingCycle.py

import re
import matplotlib.pyplot as plt
import random

class DrivingSchedule:
	'''A Class that will represent a driving cycle'''
	def __init__(self, source = '', output = '', speed = 'mph',
				pattern = r'^([0-9\.]+?)([ \t]+)([0-9\.]+?)(\n)$',
				timePattern = r'\1', speedPattern = r'\3'):
		self.source = source
		self.output = output
		self.TVdata = {} #Time mapped to velocity
		self.VAdata = {} #Velocity mapped to acceleration
		self.speed = speed #Either mph or kph
		self.pattern = pattern #Theoretically you can use custom formats
								#by passing in your own regex pattern
		self.timePattern = timePattern #If using custom regex, this should be
										#the time regex
		self.speedPattern = speedPattern #This should be the speed regex
		
	def parse(self):
		'''Reads in Driving Schedule data from the provided file according
		to the regex patterns provided, or the defaults'''
		with open(self.source, 'r') as corpus:
			for line in corpus:
				if line[0:2] == '//':
					self.speed = re.sub(r'^([/]*)([a-zA-z]*)$', r'\2',line)
				else:
					currentSpeed = float(re.sub(self.pattern, self.speedPattern, line))
					currentTime = float(re.sub(self.pattern, self.timePattern, line))
					self.TVdata[currentTime] = currentSpeed
		previousVelocity = 0
		for time in self.TVdata:
			self.VAdata[self.TVdata[time]] = self.TVdata[time] - previousVelocity
			previousVelocity = self.TVdata[time]
					
	def toKPH(self):
		'''Changes the velocity values to kph if they are in mph, checks
		this by looking at the comment at the top of the file, otherwise
		there should be no change, change is inplace'''
		if (self.speed[0].lower() == 'm'):
			self.TVdata = self.rescaleTV(1.60934)
			self.VAdata = self.rescaleVA(1.60934)
			self.speed = 'kph'
				
	def toMPH(self):
		'''Same as toKPH, but for MPH'''
		if (self.speed[0].lower() == 'k'):
			self.TVdata = self.rescaleTV(0.621371)
			self.VAdata = self.rescaleVA(0.621371)
			self.speed = 'mph'
	
	def rescaleTV(self, constant):
		'''returns scaled TV data, does not change in place'''
		answer = {}
		for time in self.TVdata:
				answer[time] = self.TVdata[time]*constant
		return answer
				
	def rescaleVA(self,constant):
		'''return scaled VA data, also does not change in place'''
		newVAdata = {}
		for velocity in self.VAdata:
			newVAdata[velocity*constant] = self.VAdata[velocity]*constant
	
	def plotTV(self):
		'''Should render a TV plot as a line graph over time, might allow
		for more calls through to pyplot if people are interested'''
		plt.plot([self.TVdata[time] for time in self.TVdata])
		plt.ylabel("Vehicle Speed (" + self.speed.strip() + ")")
		plt.xlabel("time(secs)")
		plt.show()
		
	def plotVA(self):
		'''Should render a VA plot as a scatter plot showing the power
		regions involved with the given driving schedule'''
		velocities = []
		accelerations = []
		for velocity in self.VAdata:
			 velocities.append(velocity)
			 accelerations.append(self.VAdata[velocity])
		plt.plot(velocities,accelerations,'ro')
		plt.xlabel("Velocity (" + self.speed.strip() + ")")
		plt.ylabel("Acceleration (" + self.speed.strip() + "/s)")
		plt.show()
		
	def shiftTVdata(self, timeShift=0, velocityShift=0):
		'''Returns a copy of the Driving Cycle's TV data with a constant
		shift up or down to either parameter'''
		shiftedData = {}
		for time in self.TVdata:
			shiftedData[time+timeShift] = self.TVdata[time]+velocityShift
		return shiftedData
		
	def shiftVAdata(self, velocityShift=0, accelerationShift=0):
		'''Returns a copy of the Driving Cycle's VA data with a constant
		shift up or down to either parameter'''
		shiftedData = {}
		for velocity in self.VAdata:
			shiftedData[velocity+velocityShift] = self.VAdata[velocity]+accelerationShift
		return shiftedData
		
	def jitterTVData(self, timeJitter=0, velocityJitter=0):
		'''Returns a copy of the Driving Cycle's TV data with a random
		amount added between 0 and the passed jitter parameters'''
		shiftedData = {}
		for time in self.TVdata:
			shiftedData[time+(timeJitter*random.random())] = self.VAdata[time]+(velocityJitter*random.random())
		return shiftedData
			
	def jitterVAData(self, velocityJitter=0, accelerationJitter=0):
		'''Returns a copy of the Driving Cycle's TV data with a random
		amount added between 0 and the passed jitter parameters'''
		shiftedData = {}
		for velocity in self.VAdata:
			shiftedData[velocity+(velocityJitter*random.random())] = self.VAdata[velocity]+(accelerationJitter*random.random())
		return shiftedData	
		
	def dump(self):
		'''Writes the file to the provided output'''
		with open(self.output, 'w') as output:
			output.write('//' + self.speed + "\n")
			for time in self.TVdata:
				output.write(str(time) + "\t" + str(self.TVdata[time]) + "\n")