feat(misc): add buffer-class for realtime applications

PyDynamic/misc/buffer.py

@@ -0,0 +1,36 @@
+import numpy as np
+from collections import deque
+
+# define some buffer to fill, view and consume
+class Buffer():
+
+    def __init__(self, maxlen=1000):
+        self.timestamps = deque(maxlen=maxlen)
+        self.values = deque(maxlen=maxlen)
+        self.uncertainties = deque(maxlen=maxlen)
+
+    def append(self, time=0.0, value=0.0, uncertainty=0.0):
+        self.timestamps.append(time)
+        self.values.append(value)
+        self.uncertainties.append(uncertainty)
+
+    def append_multi(self, timestamps, values, uncertainties):
+
+        for t, v, u in zip(timestamps, values, uncertainties):
+            self.append(t, v, u)
+
+    def popleft(self):
+        t = self.timestamps.popleft()
+        v = self.values.popleft()
+        u = self.uncertainties.popleft()
+        return t, v, u
+
+    def view_last(self, n):
+        r = range(-n,0)
+
+        t = np.array([self.timestamps[i] for i in r])
+        v = np.array([self.values[i] for i in r])
+        u = np.array([self.uncertainties[i] for i in r])
+
+        return t, v, u
+