diff --git a/demo/moulinrouge/tests.py b/demo/moulinrouge/tests.py
index 1ae3655..0b0b325 100644
--- a/demo/moulinrouge/tests.py
+++ b/demo/moulinrouge/tests.py
@@ -266,7 +266,6 @@ def get_test_routes(app):
         hist.add('2', [(2, 2, 8)])
         return hist.render_response()
 
-
     @app.route('/test/ylabels')
     def test_ylabels():
         chart = Line()
@@ -275,7 +274,6 @@ def get_test_routes(app):
         chart.add('line', [.0002, .0005, .00035])
         return chart.render_response()
 
-
     @app.route('/test/secondary/<chart>')
     def test_secondary_for(chart):
         chart = CHARTS_BY_NAME[chart](fill=True)
@@ -463,4 +461,15 @@ def get_test_routes(app):
 
         return pie.render_response()
 
-    return filter(lambda x: x.startswith('test'), locals())
+    @app.route('/test/legend_at_bottom/<chart>')
+    def test_legend_at_bottom_for(chart):
+        graph = CHARTS_BY_NAME[chart]()
+        graph.add('1', [1, 3, 12, 3, 4, None, 9])
+        graph.add('2', [7, -4, 10, None, 8, 3, 1])
+        graph.add('3', [7, -14, -10, None, 8, 3, 1])
+        graph.add('4', [7, 4, -10, None, 8, 3, 1])
+        graph.x_labels = ('a', 'b', 'c', 'd', 'e', 'f', 'g')
+        graph.legend_at_bottom = True
+        return graph.render_response()
+
+    return list(filter(lambda x: x.startswith('test'), locals()))
diff --git a/pygal/ghost.py b/pygal/ghost.py
index d0ebd53..e9f5c86 100644
--- a/pygal/ghost.py
+++ b/pygal/ghost.py
@@ -88,9 +88,9 @@ class Ghost(object):
     def make_series(self, series):
         return prepare_values(series, self.config, self.cls)
 
-    def make_instance(self, overrides={}):
+    def make_instance(self, overrides=None):
         self.config(**self.__dict__)
-        self.config.__dict__.update(overrides)
+        self.config.__dict__.update(overrides or {})
         series = self.make_series(self.raw_series)
         secondary_series = self.make_series(self.raw_series2)
         self._last__inst = self.cls(
@@ -99,8 +99,10 @@ class Ghost(object):
         return self._last__inst
 
     # Rendering
-    def render(self, is_unicode=False):
-        return self.make_instance().render(is_unicode=is_unicode)
+    def render(self, is_unicode=False, **kwargs):
+        return (self
+                .make_instance(overrides=kwargs)
+                .render(is_unicode=is_unicode))
 
     def render_tree(self):
         return self.make_instance().render_tree()
@@ -171,6 +173,10 @@ class Ghost(object):
         spark_options.update(kwargs)
         return self.make_instance(spark_options).render()
 
+    def _repr_svg_(self):
+        """Display svg in IPython notebook"""
+        return self.render(disable_xml_declaration=True)
+
     def _repr_png_(self):
         """Display png in IPython notebook"""
         return self.render_to_png()
diff --git a/pygal/graph/bar.py b/pygal/graph/bar.py
index 26abb15..fe266bc 100644
--- a/pygal/graph/bar.py
+++ b/pygal/graph/bar.py
@@ -37,18 +37,17 @@ class Bar(Graph):
         super(Bar, self).__init__(*args, **kwargs)
 
     def _bar(self, parent, x, y, index, i, zero,
-             shift=True, secondary=False, rounded=False):
+             secondary=False, rounded=False):
         width = (self.view.x(1) - self.view.x(0)) / self._len
         x, y = self.view((x, y))
         series_margin = width * self._series_margin
         x += series_margin
         width -= 2 * series_margin
-        if shift:
-            width /= self._order
-            x += index * width
-            serie_margin = width * self._serie_margin
-            x += serie_margin
-            width -= 2 * serie_margin
+        width /= self._order
+        x += index * width
+        serie_margin = width * self._serie_margin
+        x += serie_margin
+        width -= 2 * serie_margin
         height = self.view.y(zero) - y
         r = rounded * 1 if rounded else 0
         self.svg.transposable_node(
@@ -115,12 +114,10 @@ class Bar(Graph):
             min_0_ratio = (self.zero - self._box.ymin) / self._box.height or 1
             max_0_ratio = (self._box.ymax - self.zero) / self._box.height or 1
 
-            new_ymax = (self.zero - ymin) * (1 / min_0_ratio - 1)
-            new_ymin = -(ymax - self.zero) * (1 / max_0_ratio - 1)
             if ymax > self._box.ymax:
-                ymin = new_ymin
+                ymin = -(ymax - self.zero) * (1 / max_0_ratio - 1)
             else:
-                ymax = new_ymax
+                ymax = (self.zero - ymin) * (1 / min_0_ratio - 1)
 
             left_range = abs(self._box.ymax - self._box.ymin)
             right_range = abs(ymax - ymin) or 1
diff --git a/pygal/graph/graph.py b/pygal/graph/graph.py
index 3b100ec..52ec500 100644
--- a/pygal/graph/graph.py
+++ b/pygal/graph/graph.py
@@ -518,7 +518,7 @@ class Graph(BaseGraph):
             steps = len(y_pos)
             left_range = abs(y_pos[-1] - y_pos[0])
             right_range = abs(ymax - ymin) or 1
-            scale = right_range / (steps - 1)
+            scale = right_range / ((steps - 1) or 1)
             self._y_2nd_labels = [(self._format(ymin + i * scale), pos)
                                   for i, pos in enumerate(y_pos)]
 
diff --git a/pygal/graph/stackedbar.py b/pygal/graph/stackedbar.py
index 55ead91..27b8141 100644
--- a/pygal/graph/stackedbar.py
+++ b/pygal/graph/stackedbar.py
@@ -80,6 +80,8 @@ class StackedBar(Bar):
 
         if self.secondary_series:
             positive_vals, negative_vals = self._get_separated_values(True)
+            positive_vals = positive_vals or [self.zero]
+            negative_vals = negative_vals or [self.zero]
             self.secondary_negative_cumulation = [0] * self._len
             self.secondary_positive_cumulation = [0] * self._len
             self._pre_compute_secondary(positive_vals, negative_vals)
@@ -91,7 +93,7 @@ class StackedBar(Bar):
             max(positive_vals), self.zero)) or self.zero
 
     def _bar(self, parent, x, y, index, i, zero,
-             shift=False, secondary=False, rounded=False):
+             secondary=False, rounded=False):
         if secondary:
             cumulation = (self.secondary_negative_cumulation
                           if y < self.zero else
diff --git a/pygal/graph/verticalpyramid.py b/pygal/graph/verticalpyramid.py
index 074713a..242cd82 100644
--- a/pygal/graph/verticalpyramid.py
+++ b/pygal/graph/verticalpyramid.py
@@ -57,8 +57,8 @@ class VerticalPyramid(StackedBar):
         self._secondary_min = - self._secondary_max
 
     def _bar(self, parent, x, y, index, i, zero,
-             shift=True, secondary=False, rounded=False):
+             secondary=False, rounded=False):
         if index % 2:
             y = -y
         return super(VerticalPyramid, self)._bar(
-            parent, x, y, index, i, zero, False, secondary, rounded)
+            parent, x, y, index, i, zero, secondary, rounded)
diff --git a/pygal/test/test_config.py b/pygal/test/test_config.py
index df53d8e..48b0303 100644
--- a/pygal/test/test_config.py
+++ b/pygal/test/test_config.py
@@ -323,3 +323,34 @@ def test_inline_css(Chart):
 def test_meta_config():
     from pygal.config import CONFIG_ITEMS
     assert all(c.name != 'Unbound' for c in CONFIG_ITEMS)
+
+
+def test_label_rotation(Chart):
+    chart = Chart(x_label_rotation=28)
+    chart.add('1', [4, -5, 123, 59, 38])
+    chart.add('2', [89, 0, 8, .12, 8])
+    chart.x_labels = ['one', 'twoooooooooooooooooooooo', 'three', '4']
+    q = chart.render_pyquery()
+    if Chart in (Line, Bar):
+        assert len(q('.guides text[transform^="rotate(28"]')) == 4
+
+
+def test_legend_at_bottom(Chart):
+    chart = Chart(legend_at_bottom=True)
+    chart.add('1', [4, -5, 123, 59, 38])
+    chart.add('2', [89, 0, 8, .12, 8])
+    chart.x_labels = ['one', 'twoooooooooooooooooooooo', 'three', '4']
+    lab = chart.render()
+    chart.legend_at_bottom = False
+    assert lab != chart.render()
+
+
+def test_x_y_title(Chart):
+    chart = Chart(title='I Am A Title',
+                  x_title="I am a x title",
+                  y_title="I am a y title")
+    chart.add('1', [4, -5, 123, 59, 38])
+    chart.add('2', [89, 0, 8, .12, 8])
+    chart.x_labels = ['one', 'twoooooooooooooooooooooo', 'three', '4']
+    q = chart.render_pyquery()
+    assert len(q('.titles .title')) == 3
diff --git a/pygal/test/test_date.py b/pygal/test/test_date.py
index 391a658..73016a4 100644
--- a/pygal/test/test_date.py
+++ b/pygal/test/test_date.py
@@ -56,3 +56,9 @@ def test_date():
         '2013-02-01',
         '2013-03-01'
     ]
+
+
+def test_date_overflow():
+    datey = DateY(truncate_label=1000)
+    datey.add('dates', [1, 2, -1000000, 5, 100000000])
+    assert datey.render_pyquery()
diff --git a/pygal/test/test_graph.py b/pygal/test/test_graph.py
index 30c0a4a..b3b059b 100644
--- a/pygal/test/test_graph.py
+++ b/pygal/test/test_graph.py
@@ -21,12 +21,18 @@ import os
 import pygal
 import uuid
 import sys
+import pytest
 from pygal import i18n
 from pygal.graph.frenchmap import DEPARTMENTS, REGIONS
 from pygal.util import cut
 from pygal._compat import u
 from pygal.test import pytest_generate_tests, make_data
 
+try:
+    import cairosvg
+except ImportError:
+    cairosvg = None
+
 
 def test_multi_render(Chart, datas):
     chart = Chart()
@@ -49,12 +55,8 @@ def test_render_to_file(Chart, datas):
     os.remove(file_name)
 
 
+@pytest.mark.skipif(not cairosvg, reason="CairoSVG not installed")
 def test_render_to_png(Chart, datas):
-    try:
-        import cairosvg
-    except ImportError:
-        return
-
     file_name = '/tmp/test_graph-%s.png' % uuid.uuid4()
     if os.path.exists(file_name):
         os.remove(file_name)
@@ -62,8 +64,10 @@ def test_render_to_png(Chart, datas):
     chart = Chart()
     chart = make_data(chart, datas)
     chart.render_to_png(file_name)
+    png = chart._repr_png_()
+
     with open(file_name, 'rb') as f:
-        assert f.read()
+        assert png == f.read()
     os.remove(file_name)
 
 
@@ -353,3 +357,25 @@ def test_labels_with_links(Chart):
         assert len(links) == 4  # 3 links and 1 tooltip
     else:
         assert len(links) == 8  # 7 links and 1 tooltip
+
+
+def test_sparkline(Chart, datas):
+    chart = Chart()
+    chart = make_data(chart, datas)
+    assert chart.render_sparkline()
+
+
+def test_secondary(Chart):
+    chart = Chart()
+    rng = [83, .12, -34, 59]
+    chart.add('First serie', rng)
+    chart.add('Secondary serie',
+              map(lambda x: x * 2, rng),
+              secondary=True)
+    assert chart.render_pyquery()
+
+
+def test_ipython_notebook(Chart, datas):
+    chart = Chart()
+    chart = make_data(chart, datas)
+    assert chart._repr_svg_()
diff --git a/pygal/test/test_line.py b/pygal/test/test_line.py
index b673f14..68723d3 100644
--- a/pygal/test/test_line.py
+++ b/pygal/test/test_line.py
@@ -100,3 +100,19 @@ def test_only_major_dots():
     line.x_labels = map(str, range(12))
     q = line.render_pyquery()
     assert len(q(".dots")) == 4
+
+
+def test_line_secondary():
+    line = Line()
+    rng = [8, 12, 23, 73, 39, 57]
+    line.add('First serie', rng)
+    line.add('Secondary serie',
+             map(lambda x: x * 2, rng),
+             secondary=True)
+    line.title = "One serie"
+    q = line.render_pyquery()
+    assert len(q(".axis.x")) == 0
+    assert len(q(".axis.y")) == 1
+    assert len(q(".plot .series path")) == 2
+    assert len(q(".x.axis .guides")) == 0
+    assert len(q(".y.axis .guides")) == 7
diff --git a/pygal/test/test_view.py b/pygal/test/test_view.py
new file mode 100644
index 0000000..93dff50
--- /dev/null
+++ b/pygal/test/test_view.py
@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+# This file is part of pygal
+#
+# A python svg graph plotting library
+# Copyright © 2012-2014 Kozea
+#
+# This library is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# This library is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with pygal. If not, see <http://www.gnu.org/licenses/>.
+
+from pygal.test import pytest_generate_tests, make_data
+
+
+def test_all_logarithmic(Chart):
+    print(repr(Chart))
+    chart = Chart(logarithmic=True)
+    chart.add('1', [1, 30, 8, 199, -23])
+    chart.add('2', [87, 42, .9, 189, 81])
+    assert chart.render()
diff --git a/pygal/view.py b/pygal/view.py
index 8a93c3a..45b96b0 100644
--- a/pygal/view.py
+++ b/pygal/view.py
@@ -255,8 +255,8 @@ class PolarThetaLogView(View):
         if not hasattr(box, '_tmin') or not hasattr(box, '_tmax'):
             raise Exception(
                 'Box must be set with set_polar_box for polar charts')
-        self.log10_tmax = log10(self.box._tmax)
-        self.log10_tmin = log10(self.box._tmin)
+        self.log10_tmax = log10(self.box._tmax) if self.box._tmax > 0 else 0
+        self.log10_tmin = log10(self.box._tmin) if self.box._tmin > 0 else 0
 
     def __call__(self, rhotheta):
         """Project rho and theta"""
diff --git a/tox.ini b/tox.ini
index 20cb90c..afaa5e9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,6 +7,7 @@ deps =
      pytest
      pytest-cov
      pyquery
+     cairosvg
 
 commands =
     py.test [] --cov pygal pygal/test