Merge 905b9cb into 13e6bab

cartoframes/viz/helpers/__init__.py

@@ -9,6 +9,7 @@
 from .size_bins_layer import size_bins_layer
 from .size_category_layer import size_category_layer
 from .size_continuous_layer import size_continuous_layer
+from .cluster_size_layer import cluster_size_layer
 from .animation_layer import animation_layer
 
 
@@ -25,5 +26,6 @@ def _inspect(helper):
     'size_bins_layer',
     'size_category_layer',
     'size_continuous_layer',
+    'cluster_size_layer',
     'animation_layer'
 ]

cartoframes/viz/helpers/cluster_size_layer.py

@@ -0,0 +1,85 @@
+from __future__ import absolute_import
+
+from ..layer import Layer
+
+
+def cluster_size_layer(
+        source, value=None, resolution=32, title='', size=None,
+        color=None, description='', footer='',
+        legend=True, popup=True, widget=False, animate=None):
+    """Helper function for quickly creating a size symbol map with
+    continuous size scaled by cluster.
+
+    Args:
+        source (:py:class:`Dataset <cartoframes.data.Dataset>` or str): Dataset
+          or text representing a table or query associated with user account.
+        value (str): Column to symbolize by.
+        title (str, optional): Title of legend.
+        size (str, optiona): Min/max size array in CARTO VL syntax. Default is
+          '[2, 40]' for point geometries and '[1, 10]' for lines.
+        color (str, optional): Hex value, rgb expression, or other valid
+          CARTO VL color. Defaults is '#FFB927' for point geometries and
+          '#4CC8A3' for lines.
+        description (str, optional): Description text legend placed under legend title.
+        footer (str, optional): Footer text placed under legend items.
+        legend (bool, optional): Display map legend: "True" or "False".
+          Set to "True" by default.
+        popup (bool, optional): Display popups on hover and click: "True" or "False".
+          Set to "True" by default.
+        widget (bool, optional): Display a widget for mapped data.
+          Set to "False" by default.
+        animate (str, optional): Animate features by date/time or other numeric field.
+
+    Returns:
+        cartoframes.viz.Layer: Layer styled by `value`.
+        Includes a legend, popup and widget on `value`.
+    """
+    animation_filter = 'animation(linear(${}), 20, fade(1,1))'.format(animate) if animate else '1'
+
+    breakpoints = ', '.join([
+      'sqrt({0}^2)'.format(resolution / 8),
+      'sqrt({0}^2)'.format(resolution / 2),
+      'sqrt({0}^2)'.format(resolution)
+    ])
+
+    clusterOperation = 'clusterCount()'
+
+    return Layer(
+        source,
+        style={
+            'point': {
+                'width': 'ramp(linear({0}, viewportMIN({1}), viewportMAX({2})), [{3}])'.format(
+                    clusterOperation, clusterOperation, clusterOperation, breakpoints),
+                'color': 'opacity({0}, 0.8)'.format(color or '#FFB927'),
+                'strokeColor': 'opacity(#222, ramp(linear(zoom(), 0, 18),[0, 0.6]))',
+                'filter': animation_filter,
+                'resolution': '{0}'.format(resolution)
+            }
+        },
+        popup=popup and not animate and {
+            'hover': {
+                'title': title,
+                'value': clusterOperation
+            }
+        },
+        legend=legend and {
+            'type': {
+                'point': 'size-continuous-point'
+            },
+            'title': title,
+            'description': description,
+            'footer': footer
+        },
+        widgets=[
+            animate and {
+                'type': 'time-series',
+                'value': animate,
+                'title': 'Animation'
+            },
+            widget and {
+                'type': 'histogram',
+                'value': clusterOperation,
+                'title': 'Distribution'
+            }
+        ]
+    )