请你帮我弄清楚我的代码有什么问题。我正在尝试编写一个程序,该程序在二维中生成随机行走,并确定行走次数为 1000、最大步长为 0.9、两个位置之间的间隔为 500 步后步行者位置的统计信息0.001。
import math
import random
import time
print "RANDOM WALKS ANALYSIS IN ONE DIMENSION"
NOFW_ = 1000 #The number of walks
NOFS_= 500 #The number of steps in each walk
MSS_ = 0.9 # The maximum step size[m]
SOFP_ = 0.001 # The separation of positions considered equal[m]
print " Number of walks: %3g"% NOFW_
print " Number of steps in each Walk: %3g"% NOFS_
print " Maximum step size: %3g"% MSS_,"m"
print "Separation of positions considered equal: %3g"% SOFP_,"m"
print
print "Please wait while random walks are generated and analyzed..."
print "Date:" + time.ctime()
print
def initialPosition():
return (0.0, 0.0)
def distance(posA, posB):
"""Calculates the distance between two positions posA and posB"""
distance = math.sqrt((posB[0] - posA[0])**2 + (posB[1] - posA[1])**2)
return distance
def printstats(description, numbers):
minimum_value_ = min(numbers)
numbers.sort()
Tenth_percentile = abs(0.10*len(numbers) + 0.5)
Mean_value_ = (1./float(len(numbers))*sum(numbers))
A = 0
for values in numbers:
B = distance(values, Mean_value_)
B = B**2
A = B + A
Standard_deviation = math.sqrt((1./(len(numbers)-1))*A)
Newposition_ = int(0.90*(len(numbers) + 0.5))
Ninetieth_percentile =numbers[Newposition_]
maximum_value_ = max(numbers)
print "Analysis for"""+ description
print "Minimum value: %9.1f" % minimum_value_
print "10th percentile: %7.1f" % Tenth_percentile
print "Mean value: %12.1f" % Mean_value_
print "Standard deviation: %4.1f" % Standard_deviation
print "90th percentile: %7.1f" % Ninetieth_percentile
print "Maximum value: %9.1f" % maximum_value_
list_1 = [minimum_value_, Tenth_percentile, Mean_value_, Standard_deviation, Ninetieth_percentile,maximum_value_]
return list_1
def takeStep(prevPosition, maxStep):
x = random.random()
y = random.random()
minStep = -maxStep
Z = random.random()*2*math.pi
stepsize_ = random.random()*0.9
Stepx= stepsize_*math.cos(Z)
Stepy= stepsize_*math.sin(Z)
New_positionx = prevPosition[0] + Stepx
New_positiony = prevPosition[1] + Stepy
return (New_positionx, New_positiony)
Step_100 = []
Step_500 = []
count_list = []
for walk in range(NOFW_):
Step1 = []
Position = (0.0,0.0)
count = 0
for step in range(NOFS_):
Next_Step_ = takeStep(Position, MSS_)
for word in Step1:
if distance(Next_Step_, word) <= SOFP_:
count +=1
position = Next_Step_
Step1.append(Next_Step_)
Step_100.append(Step1[-1])
Step_500.append(Step1[-1])
count_list.append(count)
Step_100 = printstats("distance from start at step 100 [m]", Step_100)
Step_500 = printstats("distance from start at step 500 [m]", Step_500)
count_list = printstats("times position revisited", count_list)