Handle timedelta xoffsets

Author: scottshambaugh

labellines/core.py

@@ -1,10 +1,15 @@
 import warnings
 from typing import Optional, Union
-
+from datetime import timedelta
 import matplotlib.pyplot as plt
 import numpy as np
 from matplotlib.container import ErrorbarContainer
-from matplotlib.dates import DateConverter, num2date
+from matplotlib.dates import (
+    _SwitchableDateConverter,
+    ConciseDateConverter,
+    DateConverter,
+    num2date,
+)
 from matplotlib.lines import Line2D
 from more_itertools import always_iterable
 
@@ -256,15 +261,19 @@ def labelLines(
         converter = ax.xaxis.converter
     else:
         converter = ax.xaxis.get_converter()
-    if isinstance(converter, DateConverter):
+    time_classes = (_SwitchableDateConverter, DateConverter, ConciseDateConverter)
+    if isinstance(converter, time_classes):
         xvals = [
             num2date(x).replace(tzinfo=ax.xaxis.get_units())
             for x in xvals  # type: ignore
         ]
 
     txts = []
     try:
-        xoffsets = [float(xoffsets)] * len(all_lines)  # type: ignore
+        if isinstance(xoffsets, timedelta):
+            xoffsets = [xoffsets] * len(all_lines)  # type: ignore
+        else:
+            xoffsets = [float(xoffsets)] * len(all_lines)  # type: ignore
     except TypeError:
         pass
     try:

labellines/line_label.py

@@ -2,8 +2,10 @@
 
 from typing import TYPE_CHECKING
 
+import matplotlib.dates as mdates
 import matplotlib.patheffects as patheffects
 import numpy as np
+from datetime import timedelta
 from matplotlib.text import Text
 
 from .utils import normalize_xydata
@@ -177,6 +179,13 @@ def _update_anchors(self):
         x = self._line.convert_xunits(self._target_x)
         xdata, ydata = normalize_xydata(self._line)
 
+        # Convert timedelta to float if needed
+        if isinstance(self._xoffset, timedelta):
+            xoffset = mdates.date2num(self._xoffset + self._target_x) - x
+        else:
+            xoffset = self._xoffset
+
+        # Handle nan values
         mask = np.isfinite(ydata)
         if mask.sum() == 0:
             raise ValueError(f"The line {self._line} only contains nan!")
@@ -202,9 +211,9 @@ def _update_anchors(self):
 
         # Apply x offset
         if self._xoffset_logspace:
-            x *= 10**self._xoffset
+            x *= 10**xoffset
         else:
-            x += self._xoffset
+            x += xoffset
 
         # Apply y offset
         if self._yoffset_logspace: