update examples + provide solutions

Author: tacaswell

01-callable_answer.py

@@ -0,0 +1,45 @@
+from collections import deque
+import matplotlib as mpl
+import matplotlib.pyplot as plt
+import numpy as np
+plt.ion()
+
+# disable the built in key bindings
+for k in ['keymap.all_axes',
+          'keymap.back',
+          'keymap.forward',
+          'keymap.fullscreen',
+          'keymap.grid',
+          'keymap.home',
+          'keymap.pan',
+          'keymap.save',
+          'keymap.xscale',
+          'keymap.yscale',
+          'keymap.zoom']:
+    mpl.rcParams[k] = []
+
+
+fig, ax = plt.subplots()
+
+th = np.linspace(0, 2*np.pi, 64)
+ln, = ax.plot(th, np.sin(th), 'o-', picker=5)
+
+
+class FormatterCollector:
+    def __init__(self, maxlen=12):
+        self.event_deque = deque([], maxlen=maxlen)
+
+    def __call__(self, event):
+        print('called {} at ({}, {})'.format(event.name,
+                                             event.xdata,
+                                             event.ydata))
+        self.event_deque.append(event)
+
+    def collect_string(self):
+        return ''.join([ev.key for ev in self.event_deque
+                        if ev.name == 'key_press_event'])
+
+fc = FormatterCollector()
+cid = fig.canvas.mpl_connect('key_press_event', fc)
+cid2 = fig.canvas.mpl_connect('key_release_event', fc)
+cid2 = fig.canvas.mpl_connect('button_press_event', fc)

02-event_filter_answer.py

@@ -0,0 +1,78 @@
+import matplotlib.pyplot as plt
+from itertools import cycle
+import numpy as np
+plt.ion()
+
+
+class LineMaker:
+    def __init__(self, ln):
+        # stash the current data
+        self.xdata = list(ln.get_xdata())
+        self.ydata = list(ln.get_ydata())
+        # stash the Line2D artist
+        self.ln = ln
+        self.color_cyle = cycle(['#1f77b4', '#ff7f0e', '#2ca02c', '#d62728',
+                                 '#9467bd', '#8c564b', '#e377c2', '#7f7f7f',
+                                 '#bcbd22', '#17becf'])
+        self.button_cid = ln.figure.canvas.mpl_connect('button_press_event',
+                                                       self.on_button)
+        self.key_cid = ln.figure.canvas.mpl_connect('key_press_event',
+                                                    self.on_key)
+
+    def on_button(self, event):
+        # only consider events from the lines Axes
+        if event.inaxes is not self.ln.axes:
+            return
+
+        # if not the left mouse button or a modifier key
+        # is held down, bail
+        if event.button != 1 or event.key not in (None, 'shift'):
+            print('key+button: {!r}+{!r}'.format(event.key, event.button))
+            return
+
+        if event.key == 'shift':
+            # compute the distance to each point *in data space*
+            d = np.hypot(np.asarray(self.xdata) - event.xdata,
+                         np.asarray(self.ydata) - event.ydata)
+            # find the closest point
+            ix = np.argmin(d)
+            # remove that data point
+            del self.xdata[ix]
+            del self.ydata[ix]
+        else:
+            # get the event location in data-space
+            # and add to internal data list
+            self.xdata.append(event.xdata)
+            self.ydata.append(event.ydata)
+        # update the line
+        self._update_line()
+
+    def _update_line(self):
+        # update the artist data
+        self.ln.set_data(self.xdata, self.ydata)
+        # ask the GUI to re-draw the next time it can
+        self.ln.figure.canvas.draw_idle()
+
+    def on_key(self, event):
+        # This is _super_ useful for debugging!
+        # print(event.key)
+
+        # if the escape key is hit, clear the data
+        if event.key == 'escape':
+            # clear the internal data structures
+            self.xdata.clear()
+            self.ydata.clear()
+            # update the internal line
+            self._update_line()
+
+        # if the key is c (any case)
+        if event.key.lower() == 'c':
+            # change the color
+            self.ln.set_color(next(self.color_cyle))
+
+            # ask the GUI to re-draw the next time it can
+            self.ln.figure.canvas.draw_idle()
+
+fig, ax = plt.subplots()
+ln, = ax.plot([], [], '-o')
+line_maker = LineMaker(ln)

04-custom_plotting.py

@@ -2,6 +2,11 @@
 from pddc_helpers import load_bwi_data, aggregate_by_month
 plt.ion()
 
+bwi = load_bwi_data()
+bwi_monthly = aggregate_by_month(bwi)
+
+fig, ax = plt.subplots()
+
 
 def plot_aggregated_errorbar(ax, gb, label, picker=None, **kwargs):
     kwargs.setdefault('capsize', 3)
@@ -19,12 +24,34 @@ def plot_aggregated_errorbar(ax, gb, label, picker=None, **kwargs):
     ax.figure.canvas.draw_idle()
     return eb, fill
 
-bwi = load_bwi_data()
-bwi_monthly = aggregate_by_month(bwi)
+arts = plot_aggregated_errorbar(ax, bwi_monthly, 'bwi')
 
-fig, ax = plt.subplots()
-ax.set_xlabel('Date [UTC]')
-ax.set_ylabel('Air Temperature [℃]')
-ax.set_title('BWI')
+# EXERCISE
+# - make the shaded area configurable
+# - make center line configurable
 
-arts = plot_aggregated_errorbar(ax, bwi_monthly, 'bwi')
+
+def plot_aggregated_errorbar(ax, gb, label, picker=None, *,
+                             bands=None,
+                             center_line='mean',
+                             **kwargs):
+    if bands is None:
+        bands = ['min', 'max']
+    kwargs.setdefault('capsize', 3)
+    kwargs.setdefault('markersize', 5)
+    kwargs.setdefault('marker', 'o')
+    eb = ax.errorbar(gb.index, center_line,
+                     yerr='std',
+                     data=gb,
+                     label=label,
+                     picker=picker,
+                     **kwargs)
+    fill = ax.fill_between(gb.index, *bands, alpha=.5,
+                           data=gb, color=eb[0].get_color())
+    ax.legend()
+    ax.figure.canvas.draw_idle()
+    return eb, fill
+
+arts = plot_aggregated_errorbar(ax, bwi_monthly, 'bwi',
+                                bands=['25%', '75%'],
+                                center_line='50%')

05-interactive_temperature.py

@@ -1,7 +1,7 @@
 import matplotlib.pyplot as plt
-import matplotlib as mpl
 from cycler import cycler
 from pddc_helpers import (load_bwi_data, aggregate_by_month, aggregate_by_day,
+                          plot_aggregated_errorbar,
                           extract_day_of_hourly, extract_month_of_daily)
 
 
@@ -179,20 +179,29 @@ def _monthly_on_pick(self, event):
             self._plot_T_by_hour(sel_date.year, sel_date.month, sel_date.day)
 
     def _plot_T_by_hour(self, year, month, day):
+        # get the hourly data for a single day
         df = extract_day_of_hourly(self.data_by_hour, year, month, day)
+        # format the label
         label = '{:s}: {:04d}-{:02d}-{:02d}'.format(
             self.label, year, month, day)
+        # A 'simple' plot
         self.daily_ax.plot('T', '-', picker=10, label=label, data=df,
                            **next(self.style_cycle))
+        # update the legend
         self.daily_ax.legend()
+        # ask the GUI to redraw the next time it can
         self.daily_ax.figure.canvas.draw_idle()
 
     def _daily_on_pick(self, event):
         if event.mouseevent.inaxes is not self.daily_ax:
             return
+        # grab the canvas
         canvas = event.artist.figure.canvas
+        # remove the artist
         event.artist.remove()
+        # update the legend
         self.daily_ax.legend()
+        # redraw the canvas next time it is convenient
         canvas.draw_idle()
 
     def remove(self):