change from error to warn when timeseries has a zero rate (#1809)

* only warn when writing zero rates instead of error

* update changelog

CHANGELOG.md

@@ -6,7 +6,7 @@
 - For `NWBHDF5IO()`, change the default of arg `load_namespaces` from `False` to `True`. @bendichter [#1748](https://github.com/NeurodataWithoutBorders/pynwb/pull/1748)
 - Add `NWBHDF5IO.can_read()`. @bendichter [#1703](https://github.com/NeurodataWithoutBorders/pynwb/pull/1703)
 - Add `pynwb.get_nwbfile_version()`. @bendichter [#1703](https://github.com/NeurodataWithoutBorders/pynwb/pull/1703)
-- Updated timeseries data checks to warn instead of error when reading invalid files. @stephprince [#1793](https://github.com/NeurodataWithoutBorders/pynwb/pull/1793)
+- Updated timeseries data checks to warn instead of error when reading invalid files. @stephprince [#1793](https://github.com/NeurodataWithoutBorders/pynwb/pull/1793) and [#1809](https://github.com/NeurodataWithoutBorders/pynwb/pull/1809)
 - Expose the offset, conversion and channel conversion parameters in `mock_ElectricalSeries`. @h-mayorquin [#1796](https://github.com/NeurodataWithoutBorders/pynwb/pull/1796)
 
 ### Bug fixes

src/pynwb/base.py

@@ -187,10 +187,12 @@ def __init__(self, **kwargs):
             if isinstance(timestamps, TimeSeries):
                 timestamps.__add_link('timestamp_link', self)
         elif self.rate is not None:
-            if self.rate <= 0:
+            if self.rate < 0:
                 self._error_on_new_warn_on_construct(
-                    error_msg='Rate must be a positive value.'
+                    error_msg='Rate must not be a negative value.'
                 )
+            elif self.rate == 0.0 and get_data_shape(data)[0] > 1:
+                warn('Timeseries has a rate of 0.0 Hz, but the length of the data is greater than 1.')
             if self.starting_time is None:  # override default if rate is provided but not starting time
                 self.starting_time = 0.0
             self.starting_time_unit = self.__time_unit

tests/unit/test_base.py

@@ -406,10 +406,12 @@ def test_get_data_in_units(self):
         assert_array_equal(ts.get_data_in_units(), [1., 2., 3.])
 
     def test_non_positive_rate(self):
-        with self.assertRaisesWith(ValueError, 'Rate must be a positive value.'):
+        with self.assertRaisesWith(ValueError, 'Rate must not be a negative value.'):
             TimeSeries(name='test_ts', data=list(), unit='volts', rate=-1.0)
-        with self.assertRaisesWith(ValueError, 'Rate must be a positive value.'):
-            TimeSeries(name='test_ts1', data=list(), unit='volts', rate=0.0)
+
+        with self.assertWarnsWith(UserWarning,
+                                  'Timeseries has a rate of 0.0 Hz, but the length of the data is greater than 1.'):
+            TimeSeries(name='test_ts1', data=[1, 2, 3], unit='volts', rate=0.0)
 
     def test_file_with_non_positive_rate_in_construct_mode(self):
         """Test that UserWarning is raised when rate is 0 or negative
@@ -419,7 +421,7 @@ def test_file_with_non_positive_rate_in_construct_mode(self):
                                  parent=None,
                                  object_id="test",
                                  in_construct_mode=True)
-        with self.assertWarnsWith(warn_type=UserWarning, exc_msg='Rate must be a positive value.'):
+        with self.assertWarnsWith(warn_type=UserWarning, exc_msg='Rate must not be a negative value.'):
             obj.__init__(
                 name="test_ts",
                 data=list(),