def GenerateTotalTimes(self):
'''
Generate activity durations based on the quantification of the risk table
Args:
Returns: dictionary
Raises:
In the example below a risk table R has allready been created
ex::
R.GenerateTotalTimes() #generate durations based on the table
'''
times = {}
for q in self.table:
totaltime = []
for w in self.table[q]:
base_duration = self.net.GetNetworkIDDict()[q].GetDuration() #extract all durations
params = self.table[q][w]
T = triang(min=params[0], ml=params[1], max=params[2]).generate(1)[0]
totaltime.append(base_duration + T)
times[q] = sum(totaltime)
return times
def Simulate(self, n=10, WriteToDB=True, DbName="Simulation_variates.db", RiskTable = None):
'''Simulates the network. n = 10 itterations is default (which off course is not enough!)
Currently, the only avilable distribution is the triangular
distribution (http://en.wikipedia.org/wiki/Triangular_distribution)
The method allso gives you the opportunity to write the resulting endates, that is the duration (days) from
project start to the relevant activity's enddate to a database file called Simulation_variates.db using SQLite
This file is by default located in /db. You may allso simulate through a Risk table, for that see the documentation of the Driver module
Args: n (int) number of itterations
WriteToDB (boealen) if True writes the endates to database
DbName (str) Name of database to create
end (boelan) write all activity's enddates to database (not yet working)
Returns:
Writes simulation variates to SQLite DB
Raises:'''
#updating the project
#Removing old database file
DbName = self.path_to_db
try:
os.remove(DbName)
except OSError:
pass
current_durations = [activity.GetDuration() for activity in self]
if WriteToDB == True:
#Constructing appropriate database using SQLite
db_string = ""
for q in self.activities:
db_string = db_string + "ID" + str(q.GetID()) + " TEXT" + ", "
db_string_dates = "CREATE TABLE SimulationResults(" + db_string[:-2] + ")"
db_string_critical = "CREATE TABLE SimulationResults_critical(" + db_string[:-2] + ")"
#Creating database
con = lite.connect(DbName)
cur = con.cursor()
try:
cur.execute(db_string_dates)
cur.execute(db_string_critical)
except:
print "Database allready exists"
con.commit() # Save (commit) the changes
self.networkends = []
"""
This loops assigns a random duration for each activity in the
network, and calculates the endtime. This is done n times
"""
#Generates n variates
if RiskTable == None:
for i in range(n):
self.CalculateTotalFloats()
#each activity is assigned a new duration here:
for q in self.activities:
try:
Time = triang(min = q.minduration,
ml = q.mlduration,
max = q.maxduration)
T = Time.generate(1)[0]
q.AssignDuration(T)
except AttributeError:
continue
self.__ForwardPass()
#Only initiate if you want to write resukts to db
if WriteToDB == True:
#Every endate for each activity is here:
enddates = []
criticality = []
for q in self.activities:
try:
duration = q.GetEnd(asobject=True)-self.GetNetworkStart(asobject=True)
enddates.append(duration.days)
critical = q.GetSlack(free=False)
criticality.append(critical)
except AttributeError:
continue
enddates = str(tuple(enddates))
criticality= str(tuple(criticality))
db_string_dates = "INSERT INTO SimulationResults VALUES" + enddates
db_string_criticality = "INSERT INTO SimulationResults_critical VALUES" + criticality
cur.execute(db_string_dates)
cur.execute(db_string_criticality)
enddate = (self.GetNetworkEnd() - self.GetNetworkStart()).days
self.networkends.append(enddate)
else:
for i in range(n):
self.CalculateTotalFloats()
#each activity is assigned a new duration here:
T = RiskTable.GenerateTotalTimes() #this is a dict on the form {'ID':totaltime}
for ID in T:
self.GetNetworkIDDict()[ID].AssignDuration(T[ID]) #activityinstance
self.__ForwardPass()
#Only initiate if you want to write resukts to db
if WriteToDB == True:
#Every endate for each activity is here:
enddates = []
criticality = []
for q in self.activities:
try:
duration = q.GetEnd(asobject=True)-self.GetNetworkStart(asobject=True)
enddates.append(duration.days)
critical = q.GetSlack(free=False)
criticality.append(critical)
except AttributeError:
continue
enddates = str(tuple(enddates))
criticality= str(tuple(criticality))
db_string_dates = "INSERT INTO SimulationResults VALUES" + enddates
db_string_criticality = "INSERT INTO SimulationResults_critical VALUES" + criticality
cur.execute(db_string_dates)
cur.execute(db_string_criticality)
enddate = (self.GetNetworkEnd() - self.GetNetworkStart()).days
self.networkends.append(enddate)
con.commit()
con.close()
for duration, activity in zip(current_durations, self):
activity.AssignDuration(duration)