finished compare plot

poll.py

@@ -1,3 +1,6 @@
+import datetime
+from analyze import hourly_rate_of_change
+
 def sample_every_kth_point(df, k):
     # Validate the input to ensure k is positive and does not exceed the DataFrame length
     if k <= 0:
@@ -7,4 +10,48 @@ def sample_every_kth_point(df, k):
 
     # Sample every k-th point
     sampled_df = df.iloc[::k]
-    return sampled_df
+    return sampled_df
+
+def optimal_sample(df, threshold_dT=0.5):
+    t0 = df["time"].iloc[0]
+    indices = [0]
+    times = [t0]
+    for i in range(1, len(df)):
+        dT = abs(df["value"].iloc[i] - df["value"].iloc[indices[-1]])
+        if dT > threshold_dT:
+            times.append(i)
+            indices.append(i)
+    return df.iloc[indices]
+        
+def sample_reglin(df,max_dT=0.5, max_poll_interval=2 * 3600):
+    indices = []
+    def get_first_point_after(date):
+        if(df[df['time'] > date].empty):
+            raise ValueError("No point before the date")
+        return df[df['time'] > date].iloc[0]
+    # Get first two points
+    t0 = df["time"].iloc[0]
+    t1 = df["time"].iloc[1]
+    while True:
+        v0 = df[df["time"] == t0]["value"].values[0]
+        v1 = df[df["time"] == t1]["value"].values[0]
+        # Calculate the slope
+        s = abs((v1 - v0) / (t1 - t0).total_seconds())
+        #add max_dT/s to t1
+        new_t = t1 + datetime.timedelta(seconds=min(max_dT/s, max_poll_interval))
+        try:
+            new_t = get_first_point_after(new_t)["time"]
+            indices.append(df[df["time"] == new_t].index[0])
+            t0 = t1
+            t1 = new_t
+        except ValueError:
+            break
+    return df.loc[indices]
+
+def sample_avg_rate_of_change(df,poll_rate):
+    indices = [0]
+    for i in range(len(df)):
+        current_hour = df["time"].iloc[i].hour
+        if(df["time"].iloc[i] - df["time"].iloc[indices[-1]] > datetime.timedelta(seconds = poll_rate.iloc[current_hour])):
+            indices.append(i)
+    return df.iloc[indices]