diff --git a/pygal/graph/bar.py b/pygal/graph/bar.py
index 100bd97..d685227 100644
--- a/pygal/graph/bar.py
+++ b/pygal/graph/bar.py
@@ -102,27 +102,16 @@ class Bar(Graph):
                 width=bar_inner_width,
                 height=height,
                 class_='rect reactive tooltip-trigger')
-            self.svg.node(bar, 'desc', class_="value").text = val
-            tooltip_positions = map(
-                str, (x + bar_inner_width / 2, y + height / 2))
-            self.svg.node(bar, 'desc',
-                          class_="x centered"
-            ).text = tooltip_positions[int(self.horizontal)]
-            self.svg.node(bar, 'desc',
-                          class_="y centered"
-            ).text = tooltip_positions[int(not self.horizontal)]
+
+            x += bar_inner_width / 2
+            y += height / 2
+
             if self.horizontal:
-                x += .3 * self.value_font_size
-                y += height / 2
-            else:
-                y += height / 2 + .3 * self.value_font_size
-            if self.print_values:
-                self.svg.transposable_node(
-                    serie_node['text_overlay'], 'text',
-                    class_='centered',
-                    x=x + bar_inner_width / 2,
-                    y=y
-                ).text = val if self.print_zeroes or val != '0' else ''
+                x, y = y, x
+
+            self._tooltip_data(bar, val, x, y, classes="centered")
+            self._static_value(serie_node, val, x, y)
+
         return stack_vals
 
     def _compute(self):
diff --git a/pygal/graph/base.py b/pygal/graph/base.py
index 2629f90..b87f90c 100644
--- a/pygal/graph/base.py
+++ b/pygal/graph/base.py
@@ -23,7 +23,7 @@ Base for pygal charts
 
 from __future__ import division
 import io
-from pygal.serie import Serie
+from pygal.serie import Serie, Value
 from pygal.view import Margin, Box
 from pygal.util import get_text_box, get_texts_box, cut, rad, humanize
 from pygal.svg import Svg
@@ -35,6 +35,8 @@ from math import sin, cos
 class BaseGraph(object):
     """Graphs commons"""
 
+    __value__ = Value
+
     def __init__(self, config=None, **kwargs):
         """Init the graph"""
         self.config = config or Config()
@@ -51,7 +53,8 @@ class BaseGraph(object):
 
     def add(self, title, values):
         """Add a serie to this graph"""
-        self.series.append(Serie(title, values, len(self.series)))
+        self.series.append(
+            Serie(title, list(values), len(self.series), self.__value__))
 
     def reinit(self):
         """(Re-)Init the graph"""
@@ -119,6 +122,11 @@ class BaseGraph(object):
         """Getter for the maximum series size"""
         return max([len(serie.values) for serie in self.series])
 
+    @cached_property
+    def _max(self):
+        """Getter for the maximum series value"""
+        return max(self._values)
+
     def _draw(self):
         """Draw all the things"""
         self._compute()
@@ -134,6 +142,13 @@ class BaseGraph(object):
             return False
         return True
 
+    def _uniformize_data(self):
+        """Make all series to max len"""
+        for serie in self.series:
+            if len(serie.values) < self._len:
+                diff = self._len - len(serie.values)
+                serie.metadata += diff * [self.__value__(0)]
+
     def _render(self):
         """Make the graph internally"""
         self.reinit()
diff --git a/pygal/graph/graph.py b/pygal/graph/graph.py
index 2b7a6e4..164542d 100644
--- a/pygal/graph/graph.py
+++ b/pygal/graph/graph.py
@@ -36,11 +36,15 @@ class Graph(BaseGraph):
         """Draw all decorations"""
         self._set_view()
         self._make_graph()
-        self._x_axis()
-        self._y_axis()
+        self._axes()
         self._legend()
         self._title()
 
+    def _axes(self):
+        """Draw axes"""
+        self._x_axis()
+        self._y_axis()
+
     def _set_view(self):
         """Assign a view to current graph"""
         self.view = (LogView if self.logarithmic else View)(
@@ -92,14 +96,14 @@ class Graph(BaseGraph):
         self.svg.node(text, 'tspan', class_='label')
         self.svg.node(text, 'tspan', class_='value')
 
-    def _x_axis(self):
+    def _x_axis(self, draw_axes=True):
         """Make the x axis: labels and guides"""
         if not self._x_labels:
             return
 
         axis = self.svg.node(self.nodes['plot'], class_="axis x")
 
-        if 0 not in [label[1] for label in self._x_labels]:
+        if 0 not in [label[1] for label in self._x_labels] and draw_axes:
             self.svg.node(axis, 'path',
                       d='M%f %f v%f' % (0, 0, self.view.height),
                       class_='line')
@@ -107,10 +111,12 @@ class Graph(BaseGraph):
             guides = self.svg.node(axis, class_='guides')
             x = self.view.x(position)
             y = self.view.height + 5
-            self.svg.node(guides, 'path',
-                      d='M%f %f v%f' % (x, 0, self.view.height),
+            if draw_axes:
+                self.svg.node(
+                    guides, 'path',
+                    d='M%f %f v%f' % (x, 0, self.view.height),
                     class_='%sline' % (
-                        'guide ' if position != 0 else ''))
+                    'guide ' if position != 0 else ''))
             text = self.svg.node(guides, 'text',
                              x=x,
                              y=y + .5 * self.label_font_size + 5
@@ -120,14 +126,14 @@ class Graph(BaseGraph):
                 text.attrib['transform'] = "rotate(%d %f %f)" % (
                     self.x_label_rotation, x, y)
 
-    def _y_axis(self):
+    def _y_axis(self, draw_axes=True):
         """Make the y axis: labels and guides"""
         if not self._y_labels:
             return
 
         axis = self.svg.node(self.nodes['plot'], class_="axis y")
 
-        if 0 not in [label[1] for label in self._y_labels]:
+        if 0 not in [label[1] for label in self._y_labels] and draw_axes:
             self.svg.node(axis, 'path',
                       d='M%f %f h%f' % (0, self.view.height, self.view.width),
                       class_='line')
@@ -138,11 +144,13 @@ class Graph(BaseGraph):
             ))
             x = -5
             y = self.view.y(position)
-            self.svg.node(guides, 'path',
-                          d='M%f %f h%f' % (0, y, self.view.width),
-                          class_='%s%sline' % (
-                              'major ' if major else '',
-                              'guide ' if position != 0 else ''))
+            if draw_axes:
+                self.svg.node(
+                    guides, 'path',
+                    d='M%f %f h%f' % (0, y, self.view.width),
+                    class_='%s%sline' % (
+                        'major ' if major else '',
+                        'guide ' if position != 0 else ''))
             text = self.svg.node(guides, 'text',
                                  x=x,
                                  y=y + .35 * self.label_font_size,
@@ -226,3 +234,27 @@ class Graph(BaseGraph):
                     coord = tuple(reversed(coord))
                 interpolateds.append(coord)
         return interpolateds
+
+    def _tooltip_data(self, node, value, x, y, classes=None):
+        self.svg.node(node, 'desc', class_="value").text = value
+        if classes is None:
+            classes = []
+            if x > self.view.width / 2:
+                classes.append('left')
+            if y > self.view.height / 2:
+                classes.append('top')
+            classes = ' '.join(classes)
+
+        self.svg.node(node, 'desc',
+                      class_="x " + classes).text = str(x)
+        self.svg.node(node, 'desc',
+                      class_="y " + classes).text = str(y)
+
+    def _static_value(self, serie_node, value, x, y):
+        if self.print_values:
+            self.svg.node(
+                serie_node['text_overlay'], 'text',
+                class_='centered',
+                x=x,
+                y=y + self.value_font_size / 3
+            ).text = value if self.print_zeroes or value != '0' else ''
diff --git a/pygal/graph/line.py b/pygal/graph/line.py
index a486151..afc0ae2 100644
--- a/pygal/graph/line.py
+++ b/pygal/graph/line.py
@@ -75,17 +75,11 @@ class Line(Graph):
                 val = self._get_value(serie.points, i)
                 self.svg.node(dots, 'circle', cx=x, cy=y, r=2.5,
                               class_='dot reactive tooltip-trigger')
-                self.svg.node(dots, 'desc', class_="value").text = val
-                self.svg.node(dots, 'desc',
-                              class_="x " + classes).text = str(x)
-                self.svg.node(dots, 'desc',
-                              class_="y " + classes).text = str(y)
-                if self.print_values:
-                    self.svg.node(
-                        serie_node['text_overlay'], 'text',
-                        x=x + self.value_font_size,
-                        y=y + self.value_font_size,
-                    ).text = val
+                self._tooltip_data(dots, val, x, y)
+                self._static_value(
+                    serie_node, val,
+                    x + self.value_font_size,
+                    y + self.value_font_size)
 
         if self.stroke:
             if self.interpolate:
@@ -97,7 +91,7 @@ class Line(Graph):
                 class_='line reactive' + (' nofill' if not self.fill else ''))
 
     def _compute(self):
-        x_pos = [x / float(self._len - 1) for x in range(self._len)
+        x_pos = [x / (self._len - 1) for x in range(self._len)
         ] if self._len != 1 else [.5]  # Center if only one value
         for serie in self.series:
             if not hasattr(serie, 'points'):
diff --git a/pygal/graph/pie.py b/pygal/graph/pie.py
index bed33af..9b6f301 100644
--- a/pygal/graph/pie.py
+++ b/pygal/graph/pie.py
@@ -22,6 +22,7 @@ Pie chart
 """
 
 from __future__ import division
+from pygal.serie import PositiveValue
 from pygal.util import decorate
 from pygal.graph.graph import Graph
 from math import pi
@@ -30,6 +31,8 @@ from math import pi
 class Pie(Graph):
     """Pie graph"""
 
+    __value__ = PositiveValue
+
     def slice(self, serie_node, start_angle, serie, total):
         """Make a serie slice"""
 
@@ -69,11 +72,6 @@ class Pie(Graph):
                            original_start_angle, center, val)
         return serie_angle
 
-    def _compute(self):
-        for serie in self.series:
-            serie.values = map(lambda x: max(x, 0), serie.values)
-        return super(Pie, self)._compute()
-
     def _plot(self):
         total = sum(map(sum, map(lambda x: x.values, self.series)))
 
diff --git a/pygal/graph/radar.py b/pygal/graph/radar.py
index ef3e58f..f6eb9e8 100644
--- a/pygal/graph/radar.py
+++ b/pygal/graph/radar.py
@@ -23,6 +23,7 @@ Radar chart
 
 from __future__ import division
 from pygal.graph.line import Line
+from pygal.serie import PositiveValue
 from pygal.view import PolarView
 from pygal.util import deg, cached_property, compute_scale
 from math import cos, pi
@@ -31,6 +32,8 @@ from math import cos, pi
 class Radar(Line):
     """Kiviat graph"""
 
+    __value__ = PositiveValue
+
     def __init__(self, *args, **kwargs):
         self.x_pos = None
         self._rmax = None
diff --git a/pygal/graph/stackedline.py b/pygal/graph/stackedline.py
index 410735d..8779c3a 100644
--- a/pygal/graph/stackedline.py
+++ b/pygal/graph/stackedline.py
@@ -41,6 +41,7 @@ class StackedLine(Line):
         return new_values
 
     def _compute(self):
+        self._uniformize_data()
         x_pos = [x / float(self._len - 1) for x in range(self._len)
         ] if self._len != 1 else [.5]  # Center if only one value
         accumulation = [0] * self._len
diff --git a/pygal/serie.py b/pygal/serie.py
index e21fa94..176b2d3 100644
--- a/pygal/serie.py
+++ b/pygal/serie.py
@@ -18,27 +18,41 @@
 # along with pygal. If not, see <http://www.gnu.org/licenses/>.
 """
 Little helpers for series
+
 """
+from pygal.util import cut
 
 
 class Serie(object):
     """Serie containing title, values and the graph serie index"""
-    def __init__(self, title, values, index):
+    def __init__(self, title, values, index, value_class):
         self.title = title
         if isinstance(values, dict) or not hasattr(values, '__iter__'):
             values = [values]
-        self.metadata = map(Value, values)
-        self.values = [value.value for value in self.metadata]
+        self.metadata = map(value_class, values)
         self.index = index
 
+    @property
+    def values(self):
+        return cut(self.metadata, 'value')
+
 
 class Value(object):
+    """Value container"""
+
     def __init__(self, value):
         if not isinstance(value, dict):
             value = {'value': value}
         self.__dict__.update(value)
 
 
+class PositiveValue(Value):
+    """Positive or zero value container"""
+
+    def __init__(self, value):
+        super(PositiveValue, self).__init__(max(0, value))
+
+
 class Label(object):
     """A label with his position"""
     def __init__(self, label, pos):
diff --git a/pygal/svg.py b/pygal/svg.py
index 2dd3cbc..12d15e3 100644
--- a/pygal/svg.py
+++ b/pygal/svg.py
@@ -152,21 +152,11 @@ class Svg(object):
                           to[2],
                           get_radius(small_radius), int(angle > pi), to[3]),
                       class_='slice reactive tooltip-trigger')
-        self.node(node, 'desc', class_="value").text = val
-        tooltip_position = map(
-            str, diff(center, project(
-                (radius + small_radius) / 2, start_angle + angle / 2)))
-        self.node(node, 'desc',
-                      class_="x centered").text = tooltip_position[0]
-        self.node(node, 'desc',
-                      class_="y centered").text = tooltip_position[1]
-        if self.graph.print_values:
-            self.node(
-                serie_node['text_overlay'], 'text',
-                class_='centered',
-                x=tooltip_position[0],
-                y=tooltip_position[1]
-            ).text = val if self.graph.print_zeroes or val != '0%' else ''
+        x, y = diff(center, project(
+                (radius + small_radius) / 2, start_angle + angle / 2))
+
+        self.graph._tooltip_data(node, val, x, y, classes="centered")
+        self.graph._static_value(serie_node, val, x, y)
 
     def pre_render(self, no_data=False):
         """Last things to do before rendering"""