Allow user to specify output data file

gprMax/config.py

@@ -168,16 +168,12 @@ class ModelConfig:
             outputdir: string of output file directory given by input file command.
         """
 
-        if not outputdir:
+        if outputdir is not None:
-            try:
-                self.output_file_path = Path(self.args.outputfile)
-            except AttributeError:
-                self.output_file_path = sim_config.input_file_path.with_suffix("")
-        else:
-            try:
             Path(outputdir).mkdir(exist_ok=True)
             self.output_file_path = Path(outputdir, sim_config.input_file_path.stem)
-            except AttributeError:
+        elif sim_config.args.outputfile is not None:
+            self.output_file_path = Path(sim_config.args.outputfile).with_suffix("")
+        else:
             self.output_file_path = sim_config.input_file_path.with_suffix("")
 
         parts = self.output_file_path.parts

gprMax/gprMax.py

@@ -165,6 +165,7 @@ def cli():
     # Parse command line arguments
     parser = argparse.ArgumentParser(prog="gprMax", formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument("inputfile", help=help_msg["inputfile"])
+    parser.add_argument("-outputfile", "-o", help=help_msg["outputfile"])
     parser.add_argument("-n", default=args_defaults["n"], type=int, help=help_msg["n"])
     parser.add_argument("-i", type=int, help=help_msg["i"])
     parser.add_argument("-mpi", action="store_true", default=args_defaults["mpi"], help=help_msg["mpi"])