class Snapshot(models.Model):
location = models.CharField(max_length=50)
age = fields.YearField()
x = models.PositiveSmallIntegerField()
y = models.PositiveSmallIntegerField()
class Meta:
ordering = 'location', 'age', 'x', 'y'
def __unicode__(self):
return '%s old tree in %s at (%s, %s)' % (self.age, self.location, self.x, self.y)
def use(self, fuel):
return self.uses.filter(fuel=fuel).aggregate(use=Sum('use'))['use'] or (0 * J)
class WallInsulation(Insulation):
data = DataLinkField('ComponentBase', 'wall_insulation')
new = fields.CostField()
old = fields.CostField()
maintenance_cost = fields.CostField()
repair_cost = fields.CostField()
repair_rate = fields.YearField()
replacement_cost = fields.CostField()
replacement_rate = fields.YearField()
RateModel = BlanketWallInsulation
def makewith(self, data, location, building, standard, simulation):
r = BlanketWallInsulation.r(standard, building,
location.climate_zone(standard))
inner = tuple(
BlanketWallInsulation.sheets(location, building, standard))
r -= sum((i.r for i in inner if i.r), 0)
outer = RigidWallInsulation.sheets(location, building, standard, r)
size = simulation.wall_area.into('ft**2')
self.takefrom(data.group, chain(inner, outer), size,
building.blanket_wall_insulation,
building.rigid_wall_insulation)
self.save()
class CarbonFunction(models.Model):
name = models.SlugField(primary_key=True, choices=(
('low', 'Low'),
('medium', 'Meidum'),
('high', 'High')))
building = models.ForeignKey('structures.Building')
location = models.ForeignKey('locations.Location')
standard = models.ForeignKey('standards.Standard')
year = fields.YearField()
emissions = metric.GramField()
price = metric.CostPerGramField()
@property
def cost(self):
return self.emissions * self.price
class Costs(models.Model): row = models.ForeignKey(Row, related_name='costs') period = fields.YearField() lifecycle_cost = fields.CostField() efficiency_cost = fields.CostField() energy_cost = fields.CostField() energy_use = metric.KiloWattHourField() gas_use = uscs.BTUperYearField() electricity_use = uscs.BTUperYearField() class Meta: unique_together = 'row', 'period' def __unicode__(self): return 'Deltas for %s' % self.row
class Row(Results):
group = models.ForeignKey(Group, related_name='rows')
period = fields.YearField()
year = property(lambda self: int(self.period.just('years')))
years = property(lambda self: xrange(1, self.year + 1))
def __unicode__(self):
return u"%s: %s" % (self.group, self.period)
def pv(self, cost, year=None):
return self.group.pv(cost, year or self.year)
@cached_property
def base(self):
return self.group.base.row_for(self.period)
@cached_property
def options(self):
for group in self.group.options:
yield group.row_for(self.period)
class PriceIndex(models.Model):
fuel = models.ForeignKey(Fuel)
year = fields.YearField()
zone = models.ForeignKey(CensusRegion)
value = models.FloatField()
class Meta:
unique_together = 'fuel', 'year', 'zone'
ordering = 'fuel', 'year', 'zone'
verbose_name_plural = 'price indicies'
@classmethod
def upv(cls, fuel, zone, year, rate):
indicies = cls.objects.filter(fuel=fuel, zone=zone,
year__lte=year).order_by('year')
discount = lambda i: i.value / ((1 + rate)**i.year.just('year'))
return sum(map(discount, indicies))
def __unicode__(self):
return '%s price index for year %s in zone %s' % (self.fuel, self.year,
self.zone)