Change matplotlib backend to speed up plottng time (~0.25 to ~0.03 seconds)

app.py

@@ -1,3 +1,11 @@
+import matplotlib.dates as mdates
+import matplotlib.pyplot as plt
+from dateutil.relativedelta import relativedelta
+import humanize
+from dateutil.parser import isoparse
+import sparklines
+import os
+import time
 from sqlalchemy import func
 from datetime import datetime, timedelta
 import io
@@ -5,13 +13,8 @@ from flask_sqlalchemy import SQLAlchemy
 from flask import Flask, make_response, render_template, request, jsonify
 import jinja_partials
 from flask_htmx import HTMX
-import matplotlib.pyplot as plt
-import matplotlib.dates as mdates
-import os
-import sparklines
-from dateutil.parser import isoparse
-import humanize
-from dateutil.relativedelta import relativedelta
+import matplotlib
+matplotlib.use('Agg')
 
 
 app = Flask(__name__)
@@ -358,63 +361,66 @@ def get_workouts_for_user(user, workouts):
     return [get_workout_view_data(workout, user) for workout in workouts if get_workout_view_data(workout, user)]
 
 
+def format_workout_data(workout, user):
+    """
+    Formats the workout data for view.
+
+    Parameters:
+    - workout: The workout object.
+    - user: The user associated with the workout.
+
+    Returns:
+    - dict: A dictionary with formatted workout data.
+    """
+    duration = timedelta(seconds=int(workout.duration or 0))
+
+    return {
+        'id': workout.id,
+        'user_id': user.id,
+        'user_name': user.name,
+        'start_time': format_date_with_ordinal(workout.started_at, '%#H:%M %B %dth %Y'),
+        'start_time_date': workout.started_at,
+        'start_time_ago': humanize.naturaltime(workout.started_at),
+        'duration': humanize.naturaldelta(duration),
+        'duration_minutes': duration.total_seconds() / 60,
+        'average_rpm': int(workout.average_rpm or 0),
+        'min_rpm': int(workout.min_rpm or 0),
+        'max_rpm': int(workout.max_rpm or 0),
+        'calories': int(workout.calories or 0),
+        'distance': int(workout.distance or 0),
+        'bike_display_name': workout.bike.display_name,
+        'selected_graph_types': ['speed'] + (['heart_rate'] if workout.is_heart_rate_available else []),
+        'is_heart_rate_available': workout.is_heart_rate_available,
+        'is_cadence_available': workout.is_cadence_available,
+        'average_bpm': int(workout.average_bpm or 0),
+        'min_bpm': int(workout.min_bpm or 0),
+        'max_bpm': int(workout.max_bpm or 0),
+    }
+
+
 def get_workout_view_data(workout, user):
-    duration = timedelta(
-        seconds=int(workout.duration)) if workout.duration else timedelta(seconds=0)
-    average_rpm = workout.average_rpm if workout.average_rpm else 0
-    min_rpm = workout.min_rpm if workout.min_rpm else 0
-    max_rpm = workout.max_rpm if workout.max_rpm else 0
-    calories = workout.calories if workout.calories else 0
-    distance = workout.distance if workout.distance else 0
-    average_bpm = workout.average_bpm if workout.average_bpm else 0
-    min_bpm = workout.min_bpm if workout.min_bpm else 0
-    max_bpm = workout.max_bpm if workout.max_bpm else 0
-    is_heart_rate_available = workout.is_heart_rate_available
-    is_cadence_available = workout.is_cadence_available
-    start_time = workout.started_at
+    """
+    Retrieve view data for a single workout.
 
-    selected_graph_types = ['speed']
-    if is_heart_rate_available:
-        selected_graph_types.append('heart_rate')
+    Parameters:
+    - workout: The workout object.
+    - user: The user associated with the workout.
 
-    if is_cadence_available or is_heart_rate_available:
-        return {
-            'id': workout.id,
-            'user_id': user.id,
-            'user_name': user.name,
-            'start_time': format_date_with_ordinal(start_time, '%#H:%M %B %dth %Y'),
-            'start_time_date': start_time,
-            'start_time_ago': humanize.naturaltime(start_time),
-            'duration': humanize.naturaldelta(duration),
-            'duration_minutes': duration.total_seconds() / 60,
-            'average_rpm': int(average_rpm),
-            'min_rpm': int(min_rpm),
-            'max_rpm': int(max_rpm),
-            'calories': int(calories),
-            'distance': int(distance),
-            'bike_display_name': workout.bike.display_name,
-            'selected_graph_types': selected_graph_types,
-            'is_heart_rate_available': is_heart_rate_available,
-            'is_cadence_available': is_cadence_available,
-            'average_bpm': int(average_bpm),
-            'min_bpm': int(min_bpm),
-            'max_bpm': int(max_bpm),
-        }
-    else:
-        return None
+    Returns:
+    - dict or None: A dictionary containing view data if cadence or heart rate is available, otherwise None.
+    """
+    if workout.is_cadence_available or workout.is_heart_rate_available:
+        return format_workout_data(workout, user)
+    return None
 
 
 def create_graph(x_values, y_values, y_label, filename, x_label='Time'):
+    # Plotting
     fig, ax = plt.subplots()
     ax.plot(x_values, y_values)
     ax.set_xlabel(x_label)
     ax.set_ylabel(y_label)
-
-    # ax.set_title(
-    #    'Cadence Readings for Workout {}'.format(workout_id))
     ax.xaxis.set_major_formatter(mdates.DateFormatter("%H:%M"))
-
-    # set the y-axis limits to start at 0
     ax.set_ylim(bottom=0)
 
     # Save the graph to a bytes buffer
@@ -422,6 +428,7 @@ def create_graph(x_values, y_values, y_label, filename, x_label='Time'):
     plt.savefig(buffer, format='png',
                 transparent=True, bbox_inches='tight')
     buffer.seek(0)
+
     # Create a response object with the graph image
     response = make_response(buffer.getvalue())
     response.headers['Content-Type'] = 'image/png'