[WIP] Axis

mplaltair/_axis.py

@@ -203,12 +203,101 @@ def _set_label_angle(channel, ax):
         ax : matplotlib.axes
             The mapping of the axis metadata and the scale data
         """
+
+    label_angle = channel.axis.get('labelAngle')
+
+    # Sets the defaults used by altair if axis.labelAngle is not specified
+    if label_angle is None:
+        if channel.type in ['ordinal', 'nominal']:
+            label_angle = -90
+        elif channel_type in ['quantitative', 'temporal']:
+            label_angle = 0
+
+    if channel.name == 'x':
+        for label in ax.get_xticklabels():
+            label.set_rotation(-1*label_angle)
+    elif channel.name == 'y':
+        for label in ax.get_yticklabels():
+            label.set_rotation(-1*label_angle)
+
+    # Special case for temporal encoding type to improve visual appeal
     if channel.type == 'temporal' and channel.name == 'x':
         for label in ax.get_xticklabels():
             # Rotate the labels on the x-axis so they don't run into each other.
             label.set_rotation(30)
             label.set_ha('right')
 
+def _set_axis_title(channel, ax):
+    '''Sets the axis label
+
+    Currently, does not support aggregated, binned or timeUnit specified channels
+
+    Parameters
+    ----------
+    channel: parse_chart.ChannelMetadata
+        The channel data and metadata
+    ax: maptlotlib.axes
+        The matplotlib axis to be modified
+    '''
+    if channel.title:
+        if channel.name == 'x':
+            ax.set_xlabel(title)
+        elif channel.name == 'y':
+            ax.set_ylabel(title)
+    elif channel.aggregate:
+        raise NotImplementedError
+    elif channel.bin:
+        raise NotImplementedError
+    elif channel.timeUnit:
+        raise NotImplementedError
+
+def _set_axis_label_visibility(channel, ax):
+    '''Set the axis label visibility
+
+    Parameters
+    ----------
+    channel: parse_chart.ChannelMetadata
+        The channel data and metadata
+    ax: maptlotlib.axes
+        The matplotlib axis to be modified
+    '''
+    labels = channel.axis.get('labels', True)
+
+    if channel.name == 'x':
+        ax.tick_param(labelbottom=labels, labeltop=labels)
+    elif channel.name == 'y':
+        ax.tick_param(labelleft=labels, labelright=labels)
+
+def _set_axis_orientation(channel, ax):
+    '''Set the axis orientation
+
+    Parameters
+    ----------
+    channel: parse_chart.ChannelMetadata
+        The channel data and metadata
+    ax: maptlotlib.axes
+        The matplotlib axis to be modified
+    '''
+    orient = channel.axis.get('orient')
+
+    if orient is None:
+        if channel.name == 'x':
+            orient = 'bottom'
+        elif channel.name == 'y':
+            orient = 'left'
+
+    ACTIONS = {
+        'x': {
+            'top': ax.xaxis.tick_top,
+            'bottom': ax.xaxis.tick_bottom
+        },
+        'y': {
+            'left': ax.xaxis.tick_left,
+            'right': ax.xaxis.tick_right
+        }
+    }
+
+    ACTIONS[enc][orient]()
 
 def convert_axis(ax, chart):
     """Convert elements of the altair chart to Matplotlib axis properties
@@ -226,3 +315,6 @@ def convert_axis(ax, chart):
         _set_tick_locator(channel, ax)
         _set_tick_formatter(channel, ax)
         _set_label_angle(channel, ax)
+        _set_axis_title(channel, ax)
+        _set_axis_label_visibility(channel, ax)
+        _set_axis_orientation(channel, ax)

mplaltair/parse_chart.py

@@ -11,6 +11,7 @@ class ChannelMetadata(object):
         The name of the encoding channel
     data : np.array
         The data linked to the channel (temporal data is converted)
+    aggregate : str or dict
     axis : dict
     bin : boolean, None
     field : str
@@ -25,6 +26,7 @@ def __init__(self, channel, alt_chart):
         chart_dict = alt_chart.to_dict()
         self.name = channel
         self.data = self._locate_channel_data(alt_chart)
+        self.aggregate = chart_dict['encoding'][self.name].get('aggregate', {})
         self.axis = chart_dict['encoding'][self.name].get('axis', {})
         self.bin = chart_dict['encoding'][self.name].get('bin', None)
         self.field = chart_dict['encoding'][self.name].get('field', None)
@@ -112,6 +114,13 @@ def __init__(self, alt_chart):
         self.data = alt_chart.data
         self.mark = alt_chart.mark
 
+        if alt_chart.to_dict().get('config').get('axis'):
+            raise NotImplementedError
+
+        if alt_chart.to_dict().get('config').get('scale'):
+            raise NotImplementedError
+
+
         self.encoding = {}
         for k, v in alt_chart.to_dict()['encoding'].items():
             self.encoding[k] = ChannelMetadata(k, alt_chart)