Idea for Echelle Model

gistfile1.txt

class IRCSEchelle(Model):
  inputs = ()
  outputs = ('polygon_array', )
  
  slit_width = Parameter(default=5.)
  slit_length = Parameter(default=10.)
  
  def evaluate(self, slit_width, slit_length, ...):
    parray = run_idl_code(slit_width, slit_length)
    return parray
    
    
class Slicer(Model):
  inputs = ('polygon_array')
  outputs = ('mask')
  
  def evaluate(self, parray):
    return your_code_that_generates_mask(parray)
    
if __name__ = '__main__':
  echelle = IRCSEchelle()
  echelle()
  echelle.slit_width = 20.
  echelle()
  
  new_echelle = echelle | Slicer()
  new_echelle.slit_width_0 = 5
  new_echelle()