Handle rounding

pygal/bar.py

@@ -1,38 +1,38 @@
 from pygal import Serie, Margin, Label
 from pygal.svg import Svg
+from pygal.util import round_to_int, round_to_float
 from pygal.base import BaseGraph
 
 
 class Bar(BaseGraph):
     """Bar graph"""
 
-    def __init__(self, width, height, precision=5,
-               format='g', style=None):
+    def __init__(self, width, height, scale=1, style=None):
         self.width = width
         self.height = height
         self.svg = Svg(width, height, style=style)
         self.label_font_size = 12
-        self.format = format
-        self.precision = precision
         self.series = []
+        self.scale = scale
         self.x_labels = self.y_labels = self.title = None
+        rnd = round_to_float if self.scale < 1 else round_to_int
+        self.round = lambda x: rnd(x, self.scale)
 
     def add(self, title, values):
-        self.series.append(
-            Serie(title, values))
+        self.series.append(Serie(title, values))
 
-    def _label(self, label):
-        return Label(('{:.%d%s}' % (
-            self.precision, self.format)).format(label), label)
+    def _label(self, number):
+        return Label(*self.round(number))
 
     def _y_labels(self, ymin, ymax):
         step = (ymax - ymin) / 20.
+
         if not step:
             return [self._label(ymin)]
         label = ymin
-        labels = []
-        while label <= ymax:
-            labels.append(self._label(label))
+        labels = set()
+        while label < (ymax + step):
+            labels.add(self._label(label))
             label += step
         return labels
 

pygal/line.py

@@ -1,38 +1,38 @@
 from pygal import Serie, Margin, Label
 from pygal.svg import Svg
+from pygal.util import round_to_int, round_to_float
 from pygal.base import BaseGraph
 
 
 class Line(BaseGraph):
     """Line graph"""
 
-    def __init__(self, width, height, precision=5,
-               format='g', style=None):
+    def __init__(self, width, height, scale=1, style=None):
         self.width = width
         self.height = height
         self.svg = Svg(width, height, style=style)
         self.label_font_size = 12
-        self.format = format
-        self.precision = precision
         self.series = []
+        self.scale = scale
         self.x_labels = self.y_labels = self.title = None
+        rnd = round_to_float if self.scale < 1 else round_to_int
+        self.round = lambda x: rnd(x, self.scale)
 
     def add(self, title, values):
-        self.series.append(
-            Serie(title, values))
+        self.series.append(Serie(title, values))
 
-    def _label(self, label):
-        return Label(('{:.%d%s}' % (
-            self.precision, self.format)).format(label), label)
+    def _label(self, number):
+        return Label(*self.round(number))
 
     def _y_labels(self, ymin, ymax):
         step = (ymax - ymin) / 20.
+
         if not step:
             return [self._label(ymin)]
         label = ymin
-        labels = []
-        while label <= ymax:
-            labels.append(self._label(label))
+        labels = set()
+        while label < (ymax + step):
+            labels.add(self._label(label))
             label += step
         return labels
 

pygal/test/test_bar.py

@@ -3,9 +3,18 @@ from math import cos, sin
 
 
 def test_simple_bar():
-    bar = Bar(800, 600, precision=2, format='f')
+    bar = Bar(800, 600)
     rng = [12, 3, 30, 4, 40, 10, 9, 2]
     bar.add('test1', rng)
     bar.x_labels = map(str, rng)
     bar.title = "Bar test"
+    bar.render()
+
+
+def test_null_bar():
+    bar = Bar(800, 600, scale=.25)
+    rng = [1, 1]
+    bar.add('test1', rng)
+    bar.x_labels = map(str, rng)
+    bar.title = "Bar test"
     bar._in_browser()

pygal/test/test_line.py

@@ -3,14 +3,14 @@ from math import cos, sin
 
 
 def test_simple_line():
-    line = Line(800, 600, precision=2, format='f')
-    rng = range(-30, 30, 5)
+    line = Line(800, 600)
+    rng = range(-30, 31, 5)
     line.add('test1', [cos(x / 10.) for x in rng])
     line.add('test2', [sin(x / 10.) for x in rng])
     line.add('test3', [cos(x / 10.) - sin(x / 10.) for x in rng])
     line.x_labels = map(str, rng)
     line.title = "cos sin and cos - sin"
-    line.render()
+    line._in_browser()
 
 
 def test_one_dot():

pygal/test/test_util.py

@@ -0,0 +1,22 @@
+from pygal.util import round_to_int, round_to_float
+
+
+def test_round_to_int():
+    assert round_to_int(154231, 1000) == ('154000', 154000)
+    assert round_to_int(154231, 10) == ('154230', 154230)
+    assert round_to_int(154231, 100000) == ('200000', 200000)
+    assert round_to_int(154231, 50000) == ('150000', 150000)
+    assert round_to_int(154231, 500) == ('154000', 154000)
+    assert round_to_int(154231, 200) == ('154200', 154200)
+    assert round_to_int(154361, 200) == ('154400', 154400)
+
+
+def test_round_to_float():
+    assert round_to_float(12.01934, .01) == ('12.02', 12.02)
+    assert round_to_float(12.01134, .01) == ('12.01', 12.01)
+    assert round_to_float(12.1934, .1) == ('12.2', 12.2)
+    assert round_to_float(12.1134, .1) == ('12.1', 12.1)
+    assert round_to_float(12.1134, .001) == ('12.113', 12.113)
+    assert round_to_float(12.1134, .00001) == ('12.11340', 12.1134)
+    assert round_to_float(12.1934, .5) == ('12.0', 12.0)
+    assert round_to_float(12.2934, .5) == ('12.5', 12.5)

pygal/util.py

@@ -0,0 +1,18 @@
+from decimal import Decimal
+from math import floor
+
+
+def round_to_int(number, precision):
+    rounded = (int(number) + precision / 2) / precision * precision
+    return str(int(rounded)), rounded
+
+
+# def round_to_float(number, precision):
+#     decimal = Decimal(str(number))
+#     rounded = decimal.quantize(Decimal(str(precision)))
+#     return str(rounded), float(rounded)
+
+def round_to_float(number, precision):
+    rounded = Decimal(
+        floor((number + precision / 2) / precision)) * Decimal(str(precision))
+    return str(rounded), float(rounded)

pygal/view.py

@@ -14,8 +14,8 @@ class View(object):
         self.height = height
         xrng = (xmax - xmin) or 1
         yrng = (ymax - ymin) or 1
-        if yrng == 1:
-            ymin -= .5
+        # if yrng == 1:
+            # ymin -= .5x
         self.box = Box(xmin, ymin, xrng, yrng)
 
     def x(self, x):