fix issue with in-place changes to dataframes (#113)

Making deepcopy of dataframe before making performing any changes on it

bamt/networks/base.py

@@ -597,6 +597,7 @@ def fit_parameters(self, data: pd.DataFrame, n_jobs: int = 1):
  """
  Base function for parameter learning
  """
+ data = data.copy()
  if data.isnull().values.any():
  logger_network.error("Dataframe contains NaNs.")
  return