Merge branch 'nearest_vs_nearest_before'

src/pupil_labs/neon_recording/stream/stream.py

@@ -9,8 +9,15 @@
 
 class InterpolationMethod(Enum):
     NEAREST = "nearest"
+    NEAREST_BEFORE = "nearest_before"
     LINEAR = "linear"
 
+    def __eq__(self, other):
+        if isinstance(other, str):
+            return self.value == other
+
+        return super().__eq__(other)
+
 
 def _record_truthiness(self):
     for field in self.dtype.names:
@@ -39,10 +46,27 @@ def sample(self, tstamps=None, method=InterpolationMethod.NEAREST):
         if method == InterpolationMethod.NEAREST:
             return self._sample_nearest(tstamps)
 
+        if method == InterpolationMethod.NEAREST_BEFORE:
+            return self._sample_nearest_before(tstamps)
+
         elif method == InterpolationMethod.LINEAR:
             return self._sample_linear_interp(tstamps)
 
     def _sample_nearest(self, ts):
+        # Use searchsorted to get the insertion points
+        idxs = np.searchsorted(self.ts, ts)
+
+        # Ensure index bounds are valid
+        idxs = np.clip(idxs, 1, len(self.ts) - 1)
+        left = self.ts[idxs - 1]
+        right = self.ts[idxs]
+
+        # Determine whether the left or right value is closer
+        idxs -= (np.abs(ts - left) < np.abs(ts - right)).astype(int)
+
+        return self.sampler_class(self._data[idxs])
+
+    def _sample_nearest_before(self, ts):
         last_idx = len(self._data) - 1
         idxs = np.searchsorted(self.ts, ts)
         idxs[idxs > last_idx] = last_idx