71 lines
2.2 KiB
Python
71 lines
2.2 KiB
Python
"""Karma logging models."""
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import math
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import random
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import pytz
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from django.conf import settings
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from django.db import models
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class PiLogManager(models.Manager):
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"""Assemble some queries against PiLog."""
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def simulate(self):
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"""Add one more entry to the log, and return it."""
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try:
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latest = self.latest()
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except PiLog.DoesNotExist:
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latest = PiLog.objects.create(simulation_x=0.0, simulation_y=0.0,
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total_count_inside=0, total_count=0)
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latest.save()
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inside = latest.total_count_inside
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total = latest.total_count
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x = random.random()
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y = random.random()
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total += 1
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if math.hypot(x, y) < 1:
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inside += 1
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newest = PiLog.objects.create(simulation_x=x, simulation_y=y,
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total_count_inside=inside, total_count=total)
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# TODO: remove the x, y return values, now that we track them in the object
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return newest, x, y
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class PiLog(models.Model):
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"""Track pi as it is estimated over time."""
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simulation_x = models.DecimalField(max_digits=11, decimal_places=10)
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simulation_y = models.DecimalField(max_digits=11, decimal_places=10)
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total_count_inside = models.PositiveIntegerField()
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total_count = models.PositiveIntegerField()
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created = models.DateTimeField(auto_now_add=True)
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objects = PiLogManager()
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class Meta:
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"""Options for the PiLog class."""
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get_latest_by = 'created'
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def __str__(self):
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"""Provide string representation."""
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tz = pytz.timezone(settings.TIME_ZONE)
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return "({0:d}/{1:d}) @ {2:s}".format(self.total_count_inside, self.total_count,
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self.created.astimezone(tz).strftime('%Y-%m-%d %H:%M:%S %Z'))
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@property
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def value(self):
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"""Return this log entry's estimated value of pi."""
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if self.total_count == 0:
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return 0.0
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return 4.0 * int(self.total_count_inside) / int(self.total_count)
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@property
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def hit(self):
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"""Return if this log entry is inside the unit circle."""
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return math.hypot(self.simulation_x, self.simulation_y) < 1
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