diff --git a/map2loop/project.py b/map2loop/project.py
index 84aa0eea..f9220541 100644
--- a/map2loop/project.py
+++ b/map2loop/project.py
@@ -1012,7 +1012,7 @@ def draw_geology_map(self, points: pandas.DataFrame = None, overlay: str = ""):
         gdf.plot(ax=base, marker="o", color="red", markersize=5)
 
     @beartype.beartype
-    def save_mapdata_to_files(self, save_path: str = ".", extension: str = ".shp.zip"):
+    def save_mapdata_to_files(self, save_path: Union[pathlib.Path,str], extension: str = ".shp.zip"):
         """
         Saves the map data frames to csv files
 
@@ -1022,8 +1022,10 @@ def save_mapdata_to_files(self, save_path: str = ".", extension: str = ".shp.zip
             extension (str, optional):
                 An alternate extension to save the GeoDataFrame in. Defaults to ".csv".
         """
-        if not os.path.exists(save_path):
-            os.mkdir(save_path)
+        
+        save_path=pathlib.Path(save_path)
+        if not save_path.exists():
+            os.makedirs(save_path)
         self.map_data.save_all_map_data(save_path, extension)
 
     @beartype.beartype
diff --git a/map2loop/thickness_calculator.py b/map2loop/thickness_calculator.py
index eb8a2a67..099fb183 100644
--- a/map2loop/thickness_calculator.py
+++ b/map2loop/thickness_calculator.py
@@ -317,16 +317,16 @@ def compute(
         _dips = []
         _location_tracking = []
         
-        for i in range(0, len(stratigraphic_order) - 1):
+        for i in (range(1, len(stratigraphic_order) )):
             if (
                 stratigraphic_order[i] in basal_unit_list
-                and stratigraphic_order[i + 1] in basal_unit_list
+                and stratigraphic_order[i - 1] in basal_unit_list
             ):
                 basal_contact = contacts.loc[
-                    contacts["basal_unit"] == stratigraphic_order[i]
+                    contacts["basal_unit"] == stratigraphic_order[i-1]
                 ].copy()
                 top_contact = basal_contacts.loc[
-                    basal_contacts["basal_unit"] == stratigraphic_order[i + 1]
+                    basal_contacts["basal_unit"] == stratigraphic_order[i]
                 ].copy()
                 top_contact_geometry = [
                     shapely.geometry.shape(geom.__geo_interface__) for geom in top_contact.geometry
@@ -364,14 +364,18 @@ def compute(
                         p2[2] = map_data.get_value_from_raster(Datatype.DTM, p2[0], p2[1])
                         # calculate the length of the shortest line
                         line_length = scipy.spatial.distance.euclidean(p1, p2)
-                        # find the indices of the points that are within 5% of the length of the shortest line
-                        indices = shapely.dwithin(short_line, interp_points, line_length * 0.25)
+                        # find the indices of the points that are within 10% of the length of the shortest line
+                        indices = shapely.dwithin(short_line, interp_points, line_length * 1)
                         # get the dip of the points that are within
-                        _dip = numpy.deg2rad(dip[indices])
-                        _dips.append(_dip)
-                        # calculate the true thickness t = L * sin(dip)
-                        thickness = line_length * numpy.sin(_dip)
-                        
+                        if all(numpy.isnan(dip[indices])):
+                            pass
+                        else:
+                            _dip = numpy.nanmean(dip[indices])
+                            _dip = numpy.deg2rad(_dip)
+                            _dips.append(_dip)
+                            # calculate the true thickness t = L * sin(dip)
+                            thickness = line_length * numpy.sin(_dip)
+                            
                         # add location tracking
                         location_tracking = pandas.DataFrame(
                             {
@@ -384,28 +388,37 @@ def compute(
                         _location_tracking.append(location_tracking)
                         
                         # Average thickness along the shortest line
-                        if all(numpy.isnan(thickness)):
-                            pass
-                        else:
-                            _thickness.append(numpy.nanmean(thickness))
+                        _thickness.append(thickness)
 
                     # calculate the median thickness and standard deviation for the unit
                     _thickness = numpy.asarray(_thickness, dtype=numpy.float64)
-
-                    median = numpy.nanmedian(_thickness)
-                    mean = numpy.nanmean(_thickness)
-                    std_dev = numpy.nanstd(_thickness, dtype=numpy.float64)
-
-                    idx = thicknesses.index[
+                    
+                    if all(numpy.isnan(_thickness)):
+                        logger.warning(
+                    f"Cannot calculate thickness of {stratigraphic_order[i + 1]}. Near dip data not found. Assign NaN to thickness."
+                        )
+                        idx = thicknesses.index[
                         thicknesses["name"] == stratigraphic_order[i + 1]
                     ].tolist()[0]
-                    thicknesses.loc[idx, "ThicknessMean"] = mean
-                    thicknesses.loc[idx, "ThicknessMedian"] = median
-                    thicknesses.loc[idx, "ThicknessStdDev"] = std_dev
+                        thicknesses.loc[idx, "ThicknessMean"] = numpy.nan
+                        thicknesses.loc[idx, "ThicknessMedian"] = numpy.nan
+                        thicknesses.loc[idx, "ThicknessStdDev"] = numpy.nan
+                        
+                    else:
+                        median = numpy.nanmedian(_thickness)
+                        mean = numpy.nanmean(_thickness)
+                        std_dev = numpy.nanstd(_thickness, dtype=numpy.float64)
+
+                        idx = thicknesses.index[
+                            thicknesses["name"] == stratigraphic_order[i + 1]
+                        ].tolist()[0]
+                        thicknesses.loc[idx, "ThicknessMean"] = mean
+                        thicknesses.loc[idx, "ThicknessMedian"] = median
+                        thicknesses.loc[idx, "ThicknessStdDev"] = std_dev
 
             else:
                 logger.warning(
-                    f"Thickness Calculator InterpolatedStructure: Cannot calculate thickness between {stratigraphic_order[i]} and {stratigraphic_order[i + 1]}\n"
+                    f"Thickness Calculator InterpolatedStructure: Cannot calculate thickness between {stratigraphic_order[i]} and {stratigraphic_order[i - 1]}\n"
                 )
         
         # Combine all location_tracking DataFrames into a single DataFrame