Start bar/histogram

pygal/bar.py

@@ -45,14 +45,14 @@ class Bar(BaseGraph):
 
     def draw(self):
         self.validate()
-        x_step = len(self.series[0].values) + 1
-        x_pos = [x / float(x_step) for x in range(x_step)
+        x_step = len(self.series[0].values)
+        x_pos = [x / float(x_step) for x in range(x_step + 1)
         ] if x_step > 1 else [0, 1]  # Center if only one value
         x_ranges = zip(x_pos, x_pos[1:])
 
         vals = [val for serie in self.series for val in serie.values]
         margin = Margin(*(4 * [10]))
-        ymin, ymax = min(vals), max(vals)
+        ymin, ymax = 0, max(vals)
         if self.x_labels:
             x_labels = [Label(label, sum(x_ranges[i]) / 2)
                          for i, label in enumerate(self.x_labels)]
@@ -77,5 +77,5 @@ class Bar(BaseGraph):
         for serie_index, serie in enumerate(self.series):
             serie_node = self.svg.serie(serie_index)
             self.svg.bar(serie_node, [
-                ((x_ranges[i][0], v), (x_ranges[i][1], v))
+                tuple((x_ranges[i][j], v) for j in range(2))
                 for i, v in enumerate(serie.values)])

pygal/css/graph.css

@@ -98,4 +98,13 @@ svg * {
   stroke-width: 2px;
 }
 
+.series .rect {
+  opacity: .8;
+}
+
+.series .rect:hover {
+  opacity: 1;
+}
+
+
 {{ style.colors }}

pygal/line.py

@@ -37,18 +37,19 @@ class Line(BaseGraph):
         return labels
 
     def validate(self):
-        assert len(self.series)
         if self.x_labels:
             assert len(self.series[0].values) == len(self.x_labels)
         for serie in self.series:
             assert len(self.series[0].values) == len(serie.values)
 
     def draw(self):
+        vals = [val for serie in self.series for val in serie.values]
+        if not vals:
+            return
         self.validate()
         x_step = len(self.series[0].values)
         x_pos = [x / float(x_step - 1) for x in range(x_step)
         ] if x_step != 1 else [.5]  # Center if only one value
-        vals = [val for serie in self.series for val in serie.values]
         margin = Margin(*(4 * [10]))
         ymin, ymax = min(vals), max(vals)
         if self.x_labels:

pygal/svg.py

@@ -148,17 +148,24 @@ class Svg(object):
                   d='M%s L%s' % (origin, svg_values), class_='line')
 
     def bar(self, serie, values, origin=None):
-        view_values = map(lambda x: (self.view(x[0]), self.view(x[1])), values)
+        """Draw a bar graph for a serie"""
+        # value here is a list of tuple range of tuple coord
 
+        def view(rng):
+            """Project range"""
+            return (self.view(rng[0]), self.view(rng[1]))
+
+        view_values = map(view, values)
         for i, ((x, y), (X, Y)) in enumerate(view_values):
+            # x and y are left range coords and X, Y right ones
             width = X - x
             padding = .1 * width
             width = width - 2 * padding
             self.node(serie, 'rect',
-                      width=width,
-                      height=self.view.y(0) - y,
                       x=x + padding,
                       y=y,
+                      width=width,
+                      height=self.view.y(0) - y,
                       class_='rect')
 
     def render(self):

pygal/test/test_bar.py

@@ -4,7 +4,7 @@ from math import cos, sin
 
 def test_simple_bar():
     bar = Bar(800, 600, precision=2, format='f')
-    rng = [12, 3, 30, 4, 0]
+    rng = [12, 3, 30, 4, 40, 10, 9, 2]
     bar.add('test1', rng)
     bar.x_labels = map(str, rng)
     bar.title = "Bar test"

pygal/test/test_line.py

@@ -18,3 +18,14 @@ def test_one_dot():
     line.add('one dot', [12])
     line.x_labels = ['one']
     line.render()
+
+
+def test_no_dot():
+    line = Line(800, 600)
+    line.add('no dot', [])
+    line.render()
+
+
+def test_no_dot_at_all():
+    line = Line(800, 600)
+    line.render()