Vincent Davis wrote:
I ask this question in part because of a fee remarks from another question I
ask "class attribute to initiate more classes"
Basically I am simulation the process of applicants to schools and trying to
ask/answer some questions like "what conditions do you need to have an
optimal solution" Oh and to learn python. I basically had it working as a
script rather than using a class structure but it was very inflexible and I
still needed to learn about classes.
What I have these classes
class Applicant: has lots of attributes (self.gpa = random.gauss(50, 10)
about the Applicant and def() defining how/why an applicant applies to an
institution,
class Institution: Lots of attributes (self.quality = random.gauss(50,
10)) about the Institution and def() defining how the institution considers
the applicant.
class Match: this defines the interaction of the population of Applicants
and Institutions, i.e. the rules of the game and returns the outcome i.e.
which Applicants went to which Institutions.
As of now I have been running 1 Match at a time. Which is to say generate
8000 instances of Applicant and 300 instances of Institution and then run
the match Match(app_list, inst_list) and I do this with a short script.
So now I need to implement my monte-carlo. By that I mean that i want to set
some of the initial condition such as GPA, and Quality and basically re-run
the what I descried above, (generate applicant, institutions, match them)
Then save the results.
So my plan way to make a new class. This class would define the Applicant
characteristics "self.gpa = random.gauss(mean, SD)" and the
institutions self.quality = random.gauss(mean, sd)
so it would look something like this
class RepeatMatch:
def __int__(self, app_mean, app_sd, inst_mean, inst_sd, match_ repeat)
self.app_mean = app_mean
……..
self.match_repeat = match_repeat
def makeApplicants():
def makeInstitutions():
def runMatches(self)
# runs the match match_repeat number of times, saves results
# then I calculate some characteristics of the results
def ratio_dist():
# returns the Mean and sd of GPA/Quality
END OF CODE
Does it make sense to do it this way? Is there a better/alternative way of
thinking about this. In the end I want to compare the results of repeated
simulations "RepeatMatch(50,2….) Compared to RepeatMatch(50,15….)"
This is way I had ask the earlier question "class attribute to initiate more
classes"
Thanks
Vincent Davis
I worried that you might find my responses too complex, but nobody else
has responded, and it's been almost a day.
I don't see anything wrong with your approach. Since you're going to do
multiple sets of data, it makes sense for an instance of a class
(RepeatMatch) to hold the data for one such run. In your original
sample, it didn't make sense to me, but of course I didn't know where
you were heading. So I would add in instance attributes such as
self.applicants=[] to your __init__() method of RepeatMatch. (I
suspect you're planning to do exactly that)
I would caution you that each instance of RepeatMatch will then hold
lots of the other members, so keeping them around could be expensive. So
when run_matches() finishes its analysis, it might want to delete its
lists of raw data (eg. self.applicants). But other choices exist, and
you can decide that when you see how the whole thing fits together.
Perhaps you'll only have one such instance at a time. But if you're
going to do multiple things with the results, you may want this object
to hang onto the results, but throw away the raw data when all the
necessary results have been calculated.
Are you sure that the only distribution you're going to use is
random.gauss() ? If so, then you only need to pass mean and stddev to
the RepeatMatch constructor, as you're doing. But if you might need to
compare that distribution with a different one, then you might want to
use a function object, as I tried to describe earlier.
HTH
DaveA
_______________________________________________
Tutor maillist - [email protected]
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
