Surfer can use comma or period as the decimal separator. You can change the settiing in in File | Options.

1. Click File | Options.
2. In the pane on the left, click User Interface.
3. In the pane on the right, scroll to the bottom and set the Decimal separator to Period (or Comma).
4. Click OK and the decimal separators will be converted throughout the program.

Updated October, 2021