fix typo, fix calc step no_data set

preprocessor/preprocessor/preprocess.py

@@ -199,10 +199,10 @@ def preprocess_file(config: dict, file_path: os.PathLike, use_dir: os.PathLike=N
 
                 logger.info('Running preprocessing step %s' % step)
                 os.mkdir(step)
-                preprpocessor = STEP_FUNCTIONS[step]
+                preprocessor = STEP_FUNCTIONS[step]
 
                 with Timer() as step_timer:
-                    preprpocessor(previous_step, step, **step_config)
+                    preprocessor(previous_step, step, **step_config)
 
                 logger.info(
                     'Finished preprocessing step %s after %f seconds.'

preprocessor/preprocessor/steps/calc.py

@@ -26,7 +26,7 @@ def calc_step(source_dir: os.PathLike, target_dir: os.PathLike, formulas: List[d
         if isfile(target_filename):
             logger.warn('Calc output filename %s already exists' % target_filename)
 
-        calc_formula(source_dir, item['inputs'], target_filename, item['formula'], item.get('data_type', 'Float32'))
+        calc_formula(source_dir, item['inputs'], target_filename, item['formula'], item.get('data_type', 'Float32'), item.get('nodata_value', None))
 
     # take all original files with from the last step
     for filename in glob('%s/*' % source_dir):
@@ -53,6 +53,6 @@ def calc_formula(source_dir: os.PathLike, inputs: List[dict], target_filename: o
         ])
 
     if nodata_value is not None:
-        cmd.extend("--NoDataValue=%f" % nodata_value)
+        cmd.append("--NoDataValue=%f" % nodata_value)
 
     subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)