get_tight_single_resource_liquid_op_offsets in absolute space (#418)

Author: ben-ray

pylabrobot/liquid_handling/utils.py

@@ -64,6 +64,7 @@ def get_tight_single_resource_liquid_op_offsets(
 
   channel_space = (num_channels - 1) * min_spacing_between_channels
 
+  # offsets are in absolute space.
   if resource.get_absolute_rotation().z % 180 == 0:
     min_y = (resource.get_size_y() - channel_space) / 2
     if min_y < min_spacing_edge:
@@ -74,7 +75,7 @@ def get_tight_single_resource_liquid_op_offsets(
   elif resource.get_absolute_rotation().z % 90 == 0:
     min_x = (resource.get_size_x() - channel_space) / 2
     offsets = [
-      Coordinate(min_x + i * min_spacing_between_channels, 0, 0) for i in range(num_channels)
+      Coordinate(0, min_x + i * min_spacing_between_channels, 0) for i in range(num_channels)
     ][::-1]
   else:
     raise ValueError("Only 90 and 180 degree rotations are supported for now.")