Add missing files. Rename scales.

CHANGELOG.rst

@@ -2,8 +2,8 @@
 -----
 
 * Expanded unit tests for :class:`.Scale` subclasses.
-* Implemented :class:`.Monthly` scale type.
-* Implemented :class:`.Annual` scale type.
+* Implemented :class:`.Months` scale type.
+* Implemented :class:`.Years` scale type.
 * Zero lines now render above other tick marks. (#31)
 * Fixed rendering of :class:`.Bar` and :class:`.Column` shapes for negative values. (#52)
 * Refactored the :class:`.Lattice` API.

docs/api/scales.rst

@@ -13,4 +13,6 @@ Scales
 
 .. autoclass:: leather.Temporal
 
-.. autoclass:: leather.Annual
+.. autoclass:: leather.Years
+
+.. autoclass:: leather.Months

leather/__init__.py

@@ -6,7 +6,7 @@
 from leather.grid import Grid
 from leather.lattice import Lattice
 from leather.legend import Legend
-from leather.scales import Scale, Annual, Linear, Monthly, Ordinal, Temporal
+from leather.scales import Scale, Linear, Months, Ordinal, Temporal, Years
 from leather.series import Series, key_function
 from leather.shapes import Shape, Bars, Columns, Dots, Lines, style_function
 from leather import theme

leather/scales/__init__.py

@@ -1,8 +1,8 @@
 #!/usr/bin/env python
 
-from leather.scales.annual import Annual
 from leather.scales.base import Scale
 from leather.scales.linear import Linear
-from leather.scales.monthly import Monthly
+from leather.scales.months import Months
 from leather.scales.ordinal import Ordinal
 from leather.scales.temporal import Temporal
+from leather.scales.years import Years

leather/scales/months.py

@@ -0,0 +1,100 @@
+#!/usr/bin/env python
+
+from datetime import datetime, date
+import math
+
+from leather.scales.temporal import Temporal
+
+
+def to_month_count(d):
+    return (d.year * 12) + d.month
+
+
+class Months(Temporal):
+    """
+    A scale that maps years and months to a coordinate range.
+
+    This scale takes dates and datetimes, but treats them as ordinal values for
+    purposes of projection. Thus you can use this scale to render
+    :class:`.Bars` or :class:`.Columns` for yearly data.
+
+    :param domain_min:
+        The minimum value of the domain.
+    :param domain_max:
+        The maximum value of the domain.
+    """
+    def __init__(self, domain_min, domain_max):
+        self._min = self._value_as_date(domain_min)
+        self._max = self._value_as_date(domain_max)
+
+    def _value_as_date(self, value):
+        """
+        Convert a date or number to a date for consistent logic.
+        """
+        if isinstance(value, (datetime, date)):
+            return value
+
+        raise ValueError('Unsupported domain value for Annual scale.')
+
+    def project(self, value, range_min, range_max):
+        """
+        Project a value in this scale's domain to a target range.
+        """
+        d = self._value_as_date(value)
+
+        segments = to_month_count(self._max) - to_month_count(self._min) + 1
+        segment_size = float(range_max - range_min) / segments
+
+        pos = to_month_count(d) - to_month_count(self._min)
+
+        return range_min + ((pos + 0.5) * segment_size)
+
+    def project_interval(self, value, range_min, range_max):
+        """
+        Project a value in this scale's domain to an interval in the target
+        range. This is used for places :class:`.Bars` and :class:`.Columns`.
+        """
+        d = self._value_as_date(value)
+
+        segments = to_month_count(self._max) - to_month_count(self._min) + 1
+        segment_size = float(range_max - range_min) / segments
+        gap = segment_size * 0.05
+
+        pos = to_month_count(d) - to_month_count(self._min)
+        a = pos
+        b = pos
+
+        if pos >= 0:
+            b += 1
+        else:
+            a -= 1
+
+        a = range_min + (a * segment_size) + gap
+        b = range_min + (b * segment_size) - gap
+
+        return (a, b)
+
+    def ticks(self, count):
+        """
+        Generate a series of ticks for this scale.
+        """
+        a = to_month_count(self._min)
+        b = to_month_count(self._max)
+
+        size = int(math.ceil(float(b - a) / (count - 1)))
+        values = []
+
+        for i in range(count):
+            month_count = a + (size * i)
+            years = month_count // 12
+            months = month_count % 12
+
+            values.append(date(years, months, 1))
+
+        return values
+
+    def format_tick(self, value, i, count):
+        """
+        Display only year component.
+        """
+        return '%i-%i' % (value.year, value.month + 1)

leather/scales/annual.py → leather/scales/years.py

@@ -7,7 +7,7 @@
 from leather.scales.temporal import Temporal
 
 
-class Annual(Temporal):
+class Years(Temporal):
     """
     A scale that maps years to a coordinate range.
 

test.py

@@ -14,5 +14,5 @@
 chart.add_columns(data)
 chart.add_lines(data)
 chart.add_dots(data)
-chart.set_x_scale(leather.Monthly(datetime.date(2010, 1, 1), datetime.date(2014, 1, 1)))
+chart.set_x_scale(leather.Months(datetime.date(2010, 1, 1), datetime.date(2014, 1, 1)))
 chart.to_svg('test.svg')

tests/test_scales.py

@@ -106,33 +106,33 @@ def test_ticks(self):
         self.assertEqual(ticks[-1], date(2014, 1, 1))
 
 
-class TestAnnual(XMLTest):
+class TestYears(XMLTest):
     def test_project(self):
-        scale = leather.Annual(date(2010, 1, 1), date(2014, 1, 1))
+        scale = leather.Years(date(2010, 1, 1), date(2014, 1, 1))
 
         self.assertEqual(scale.project(date(2011, 1, 1), 0, 20), 6)
         self.assertEqual(scale.project(date(2012, 1, 1), 0, 20), 10)
         self.assertEqual(scale.project(date(2009, 1, 1), 0, 20), -6)
 
-        scale = leather.Annual(datetime(2010, 1, 1), datetime(2014, 1, 1))
+        scale = leather.Years(datetime(2010, 1, 1), datetime(2014, 1, 1))
 
         self.assertEqual(scale.project(datetime(2011, 1, 1), 0, 20), 6)
         self.assertEqual(scale.project(datetime(2012, 1, 1), 0, 20), 10)
         self.assertEqual(scale.project(datetime(2009, 1, 1), 0, 20), -6)
 
-        scale = leather.Annual(2010, 2014)
+        scale = leather.Years(2010, 2014)
 
         self.assertEqual(scale.project(2011, 0, 20), 6)
         self.assertEqual(scale.project(2012, 0, 20), 10)
         self.assertEqual(scale.project(2009, 0, 20), -6)
 
     def test_project_interval(self):
-        scale = leather.Annual(date(2010, 1, 1), date(2014, 1, 1))
+        scale = leather.Years(date(2010, 1, 1), date(2014, 1, 1))
 
         self.assertEqual(scale.project_interval(date(2011, 1, 1), 0, 20), (4.2, 7.8))
 
     def test_ticks(self):
-        scale = leather.Annual(date(2010, 1, 1), date(2014, 1, 1))
+        scale = leather.Years(date(2010, 1, 1), date(2014, 1, 1))
 
         self.assertEqual(scale.ticks(5), [
             date(2010, 1, 1),
@@ -143,35 +143,35 @@ def test_ticks(self):
         ])
 
 
-class TestMonthly(XMLTest):
+class TestMonths(XMLTest):
     """
     See notes for :class:`.TestTemporal`.
     """
     def test_project(self):
-        scale = leather.Monthly(date(2010, 1, 1), date(2014, 1, 1))
+        scale = leather.Months(date(2010, 1, 1), date(2014, 1, 1))
 
         self.assertAlmostEqual(scale.project(date(2011, 1, 1), 0, 48), 12, 0)
         self.assertAlmostEqual(scale.project(date(2012, 1, 1), 0, 48), 24, 0)
         self.assertAlmostEqual(scale.project(date(2008, 12, 1), 0, 48), -12, 0)
 
-        scale = leather.Monthly(datetime(2010, 1, 1), datetime(2014, 1, 1))
+        scale = leather.Months(datetime(2010, 1, 1), datetime(2014, 1, 1))
 
         self.assertAlmostEqual(scale.project(datetime(2011, 1, 1), 0, 48), 12, 0)
         self.assertAlmostEqual(scale.project(datetime(2012, 1, 1), 0, 48), 24, 0)
         self.assertAlmostEqual(scale.project(datetime(2008, 12, 1), 0, 48), -12, 0)
 
         with self.assertRaises(ValueError):
-            scale = leather.Monthly(2010, 2014)
+            scale = leather.Months(2010, 2014)
 
     def test_project_interval(self):
-        scale = leather.Monthly(date(2010, 1, 1), date(2014, 1, 1))
+        scale = leather.Months(date(2010, 1, 1), date(2014, 1, 1))
 
         a, b = scale.project_interval(date(2011, 1, 1), 0, 48)
         self.assertAlmostEqual(a, 11.5, 0)
         self.assertAlmostEqual(b, 12.5, 0)
 
     def test_ticks(self):
-        scale = leather.Monthly(date(2010, 1, 1), date(2014, 1, 1))
+        scale = leather.Months(date(2010, 1, 1), date(2014, 1, 1))
 
         self.assertEqual(scale.ticks(5), [
             date(2010, 1, 1),
@@ -181,7 +181,7 @@ def test_ticks(self):
             date(2014, 1, 1)
         ])
 
-        scale = leather.Monthly(date(2010, 1, 1), date(2012, 1, 1))
+        scale = leather.Months(date(2010, 1, 1), date(2012, 1, 1))
 
         self.assertEqual(scale.ticks(5), [
             date(2010, 1, 1),