created TimeseriesUtilities to hold gap detection routines

geomagio/TimeseriesUtilities.py

+"""Timeseries Utilities"""
+import numpy.ma as ma
+import obspy
+import numpy
+
+def get_timeseries_gaps(timeseries, channels, starttime, endtime):
+    gaps = {}
+    for channel in channels:
+        stream_gap = get_stream_gaps(
+                timeseries.select(channel=channel), starttime, endtime)
+        gaps[channel] = stream_gap
+
+    return gaps
+
+
+def get_stream_gaps(stream, starttime, endtime):
+    gaps = []
+    gap = None
+
+    i = 0
+    data = stream[0].data
+    length = len(data)
+    for i in xrange(0, length):
+        if numpy.isnan(data[i]) and gap is None:
+            gap = [starttime + i * 60]
+        if not numpy.isnan(data[i]) and gap is not None:
+            gap.append(starttime + (i - 1) * 60)
+            gaps.append(gap)
+            gap = None
+    if gap is not None:
+        gap.append(endtime)
+        gaps.append(gap)
+
+    return gaps
+
+def get_merged_gaps(gaps, channels):
+    all_gaps = []
+    gap_stream = []
+    for channel in channels:
+        gap_stream.extend(gaps[channel])
+
+    sorted_gaps = sorted(gap_stream, key=lambda starttime: starttime[1])
+    merged_gaps = []
+    new_gap = None
+    gap = sorted_gaps[0]
+    for i in range(1,len(sorted_gaps)):
+        nxtgap = sorted_gaps[i]
+        if nxtgap[0] >= gap[0] and nxtgap[0] <= gap[1]:
+            if nxtgap[1] > gap[1]:
+                gap[1] = nxtgap[1]
+        else:
+            merged_gaps.append(gap)
+            gap = nxtgap
+    merged_gaps.append(gap)
+
+    return merged_gaps