pep8 and small refactoring to make more presentable

examples/streaming.py

@@ -1,3 +1,5 @@
+from __future__ import division
+
 import math
 
 from collections import OrderedDict
@@ -14,20 +16,77 @@
 import datashader as ds
 import datashader.transfer_functions as tf
 
-# Setup UI Components --------------------
-def on_time_select_change(attr, old, new):
-    global time_period, counter, time_select_options
-    time_period = time_select_options[new]
-    counter = 0
-    bin_data()
-
 def bin_data():
     global time_period, grouped, group_count, counter, times, groups
     grouped = df.groupby([times.hour, times.minute // time_period])
     groups = sorted(grouped.groups.keys(), key=lambda r: (r[0], r[1]))
     group_count = len(groups)
     counter = 0
 
+def on_time_select_change(attr, old, new):
+    global time_period, counter, time_select_options
+    time_period = time_select_options[new]
+    counter = 0
+    bin_data()
+
+counter = 0
+def update_data():
+    global dims, grouped, group_count, counter, time_text, time_period
+
+    dims_data = dims.data
+
+    if not dims_data['width'] or not dims_data['height']:
+        return
+
+    group_num = counter % group_count
+    group = groups[group_num]
+    grouped_df = grouped.get_group(group)
+    update_image(grouped_df)
+
+    # update time text
+    num_minute_groups = 60 // time_period
+    mins = group[1] * time_period
+    hr = group[0]
+    end_mins = ((group[1] + 1) % num_minute_groups) * time_period
+    end_hr = hr if end_mins > 0 else (hr + 1) % 24
+    time_text.text = 'Time Period: {}:{} - {}:{}'.format(str(hr).zfill(2),
+                                                         str(mins).zfill(2),
+                                                         str(end_hr).zfill(2),
+                                                         str(end_mins).zfill(2))
+    counter += 1
+
+def update_image(dataframe):
+    global dims
+    dims_data = dims.data
+
+    if not dims_data['width'] or not dims_data['height']:
+        return
+
+    plot_width = int(math.ceil(dims_data['width'][0]))
+    plot_height = int(math.ceil(dims_data['height'][0]))
+    x_range = (dims_data['xmin'][0], dims_data['xmax'][0])
+    y_range = (dims_data['ymin'][0], dims_data['ymax'][0])
+
+    canvas = ds.Canvas(plot_width=plot_width,
+                       plot_height=plot_height,
+                       x_range=x_range,
+                       y_range=y_range)
+
+    agg = canvas.points(dataframe, 'dropoff_x', 'dropoff_y',
+                        ds.count('trip_distance'))
+
+    img = tf.interpolate(agg, cmap=BuGn9, how='log')
+
+    new_data = {}
+    new_data['image'] = [img.data]
+    new_data['x'] = [x_range[0]]
+    new_data['y'] = [y_range[0]]
+    new_data['dh'] = [y_range[1] - y_range[0]]
+    new_data['dw'] = [x_range[1] - x_range[0]]
+
+    image_source.stream(new_data, 1)
+
+
 time_select_options = OrderedDict()
 time_select_options['1 Hour'] = 60
 time_select_options['30 Minutes'] = 30
@@ -39,26 +98,21 @@ def bin_data():
 
 time_text = Paragraph(text='Time Period')
 
-# load nyc taxi data -------------------------------
+# load nyc taxi data
 path = './data/nyc_taxi.csv'
 datetime_field = 'tpep_dropoff_datetime'
 cols = ['dropoff_x', 'dropoff_y', 'trip_distance', datetime_field]
+
 df = pd.read_csv(path, usecols=cols, parse_dates=[datetime_field]).dropna(axis=0)
 times = pd.DatetimeIndex(df[datetime_field])
-group_count = None
-grouped = None
-groups = None
+group_count = grouped = groups = None
 bin_data()
 
-# Manage client-side dimensions --------------------
-def update_dims(attr, old, new):
-    pass
-
+# manage client-side dimensions
 dims = ColumnDataSource(data=dict(width=[], height=[], xmin=[], xmax=[], ymin=[], ymax=[]))
-dims.on_change('data', update_dims)
+dims.on_change('data', lambda a, b, c: None)
 
 dims_jscode = """
-
 var update_dims = function () {
     var new_data = {};
     new_data['height'] = [plot.get('frame').get('height')];
@@ -74,7 +128,7 @@ def update_dims(attr, old, new):
     clearTimeout(throttle);
 }
 
-throttle = setTimeout(update_dims, 200, "replace");
+throttle = setTimeout(update_dims, 100, "replace");
 """
 
 # Create plot -------------------------------
@@ -102,64 +156,9 @@ def update_dims(attr, old, new):
 image_source = ColumnDataSource(dict(image=[], x=[], y=[], dw=[], dh=[]))
 fig.image_rgba(source=image_source, image='image', x='x', y='y', dw='dw', dh='dh', dilate=False)
 
-def update_image(dataframe):
-    global dims
-    dims_data = dims.data
-
-    if not dims_data['width'] or not dims_data['height']:
-        return
-
-    plot_width = int(math.ceil(dims_data['width'][0]))
-    plot_height = int(math.ceil(dims_data['height'][0]))
-    x_range = (dims_data['xmin'][0], dims_data['xmax'][0])
-    y_range = (dims_data['ymin'][0], dims_data['ymax'][0])
-
-    canvas = ds.Canvas(plot_width=plot_width,
-                       plot_height=plot_height,
-                       x_range=x_range,
-                       y_range=y_range)
-
-    agg = canvas.points(dataframe, 'dropoff_x', 'dropoff_y', ds.count('trip_distance'))
-    img = tf.interpolate(agg, cmap=BuGn9, how='log')
-
-    new_data = {}
-    new_data['image'] = [img.data]
-    new_data['x'] = [x_range[0]]
-    new_data['y'] = [y_range[0]]
-    new_data['dh'] = [y_range[1] - y_range[0]]
-    new_data['dw'] = [x_range[1] - x_range[0]]
-
-    image_source.stream(new_data, 1)
-
 time_text = Paragraph(text='Time Period: 00:00 - 00:00')
 controls = HBox(children=[time_text, time_select], width=fig.plot_width)
 layout = VBox(children=[fig, controls])
 
-counter = 0
-def update_data():
-    global dims, grouped, group_count, counter, time_text, time_period
-
-    dims_data = dims.data
-
-    if not dims_data['width'] or not dims_data['height']:
-        return
-
-    group_num = counter % group_count
-    group = groups[group_num]
-    grouped_df = grouped.get_group(group)
-    update_image(grouped_df)
-
-    # update time text
-    num_minute_groups = 60 // time_period
-    mins = group[1] * time_period
-    hr = group[0]
-    end_mins = ((group[1] + 1) % num_minute_groups) * time_period
-    end_hr = hr if end_mins > 0 else (hr + 1) % 24
-    time_text.text = 'Time Period: {}:{} - {}:{}'.format(str(hr).zfill(2),
-                                                         str(mins).zfill(2),
-                                                         str(end_hr).zfill(2),
-                                                         str(end_mins).zfill(2))
-    counter += 1
-
 curdoc().add_root(layout)
 curdoc().add_periodic_callback(update_data, 1000)