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134 lines
4.7 KiB
134 lines
4.7 KiB
# igc2kmz scale functions |
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# Copyright (C) 2008 Tom Payne |
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# |
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# This program is free software: you can redistribute it and/or modify |
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# it under the terms of the GNU General Public License as published by |
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# the Free Software Foundation, either version 3 of the License, or |
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# (at your option) any later version. |
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# |
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# This program is distributed in the hope that it will be useful, |
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# but WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU General Public License for more details. |
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# |
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# You should have received a copy of the GNU General Public License |
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# along with this program. If not, see <http://www.gnu.org/licenses/>. |
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import datetime |
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import itertools |
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import time |
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import util |
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class Scale(object): |
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"""A linear scale.""" |
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def __init__(self, range, title=None, gradient=None, step=1, |
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max_divisions=16): |
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self.range = range |
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self.title = title |
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self.gradient = gradient |
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def steps(step=None): |
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while True: |
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yield step |
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yield 2 * step |
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yield 5 * step |
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step *= 10 |
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if step: |
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for step in steps(step): |
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lower = int(self.range[0] / step) |
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upper = int(self.range[1] / step) |
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if self.range[0] < step * lower: |
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lower -= 1 |
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if self.range[1] > step * upper: |
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upper += 1 |
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if upper - lower <= max_divisions: |
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self.grid_step = '%.1f' % (100.0 / (upper - lower)) |
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self.range = (step * lower, step * upper) |
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self.step = step |
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break |
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def normalize(self, value): |
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"""Normalize value.""" |
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if value < self.range[0]: |
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return 0.0 |
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elif self.range[1] <= value: |
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return 1.0 |
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else: |
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return float(value - self.range[0]) \ |
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/ (self.range[1] - self.range[0]) |
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def discretize(self, value, n=32): |
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"""Discretize value.""" |
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if value < self.range[0]: |
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return 0 |
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elif value > self.range[1]: |
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return n - 1 |
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else: |
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result = int(round(n * self.normalize(value))) |
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return n - 1 if result > n - 1 else result |
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def color(self, value): |
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"""Return the color for value.""" |
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return self.gradient(self.normalize(value)) |
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def colors(self, n=32): |
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"""Return the colors.""" |
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return [self.gradient(float(i) / (n - 1)) for i in xrange(0, n)] |
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class ZeroCenteredScale(Scale): |
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"""A bilinear scale centered on zero.""" |
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def normalize(self, value): |
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"""Normalize value.""" |
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if value < 0.0: |
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if value < self.range[0]: |
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return 0.0 |
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else: |
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return 0.5 - 0.5 * value / self.range[0] |
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elif value == 0.0: |
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return 0.5 |
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else: |
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if self.range[1] <= value: |
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return 1.0 |
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else: |
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return 0.5 + 0.5 * value / self.range[1] |
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class TimeScale(Scale): |
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def __init__(self, range, title=None, gradient=None, step=1, |
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max_divisions=16, tz_offset=datetime.timedelta(0, 0)): |
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def steps(step=None): |
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steps = [1, 5, 15, 30, 60, |
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5 * 60, 15 * 60, 30 * 60, |
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3600, 3 * 3600, 6 * 3600, 12 * 3600] |
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return itertools.imap(lambda s: datetime.timedelta(0, s), |
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itertools.dropwhile(lambda s: s < step, |
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steps)) |
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lower, upper = range |
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if step: |
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for step in steps(step): |
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lower = util.datetime_floor(range[0], step) |
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upper = util.datetime_floor(range[1], step) |
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if upper < range[1]: |
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upper += step |
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if (upper - lower).seconds / step.seconds < max_divisions: |
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range = (int(time.mktime(lower.timetuple())), |
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int(time.mktime(upper.timetuple()))) |
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self.grid_step = '%.1f' % (100.0 * step.seconds |
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/ (upper - lower).seconds) |
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self.step = step |
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break |
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Scale.__init__(self, range, title=title, gradient=gradient, step=None) |
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self.labels, self.positions = [], [] |
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t = datetime.datetime(lower.year, lower.month, lower.day, lower.hour) \ |
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+ self.step |
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while t < upper: |
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self.labels.append((t + tz_offset).strftime('%H:%M')) |
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self.positions.append('%1.f' % (100.0 * (t - lower).seconds |
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/ (upper - lower).seconds)) |
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t += self.step
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