Bug fix: cast reference_wind_height to float (#507)

* Change reference_wind_height to float

* Change input converter from int to float for reference_wind_height

* Make reference hub height compatible with float inputs, avoid exact comparisons

floris/simulation/flow_field.py

@@ -34,7 +34,7 @@ class FlowField(FromDictMixin):
     wind_shear: float = field(converter=float)
     air_density: float = field(converter=float)
     turbulence_intensity: float = field(converter=float)
-    reference_wind_height: int = field(converter=int)
+    reference_wind_height: float = field(converter=float)
     time_series : bool = field(default=False)
 
     n_wind_speeds: int = field(init=False)

floris/tools/floris_interface.py

@@ -66,12 +66,12 @@ def __init__(self, configuration: dict | str | Path, het_map=None):
         self.floris.flow_field.het_map = het_map
 
         # If ref height is -1, assign the hub height
-        if self.floris.flow_field.reference_wind_height == -1:
+        if np.abs(self.floris.flow_field.reference_wind_height + 1.0) < 1.0e-6:
             self.assign_hub_height_to_ref_height()
 
         # Make a check on reference height and provide a helpful warning
-        unique_heights = np.unique(self.floris.farm.hub_heights)
-        if (len(unique_heights) == 1) and (self.floris.flow_field.reference_wind_height != unique_heights[0]):
+        unique_heights = np.unique(np.round(self.floris.farm.hub_heights, decimals=6))
+        if (len(unique_heights) == 1) and (np.abs(self.floris.flow_field.reference_wind_height - unique_heights[0]) > 1.0e-6):
             err_msg = "The only unique hub-height is not the equal to the specified reference wind height.  If this was unintended use -1 as the reference hub height to indicate use of hub-height as reference wind height."
             self.logger.warning(err_msg, stack_info=True)