code: def preproc(self, which='sin', **kwargs):
          
          self.app_main(**kwargs)
          config = self.exp_config
          config['infile'] = infile = osp.join(config['expdir'], 'input.dat')
  
          func = getattr(np, which)  # np.sin, np.cos or np.tan
          data = func(np.linspace(-np.pi, np.pi))
          self.logger.info('Saving input data to %s', infile)
          np.savetxt(infile, data)
docs: Create preprocessing data
  
          Parameters
          ----------
          which: str
              The name of the numpy function to apply
          ``**kwargs``
              Any other parameter for the
              :meth:`model_organization.ModelOrganizer.app_main` method