def x_operator(field, regressors):
new_field = copy.deepcopy(field)
if derivative_order > 0:
new_field = PolyD({'t': derivative_order}) * new_field
new_field.append(regressors)
if rational:
new_field.append(new_field.__rtruediv__(1.0))
new_field = Poly(polynomial_order) * new_field
return new_field
def x_operator(field, regressors):
'field = [M, C]'
new_field = copy.deepcopy(field)
new_field = PolyD({'t': target_derivative_order - 1}) * new_field
"[M, C, M', C', M'', C'' ...]"
if rational:
new_field.append(new_field.__rtruediv__(1.0))
new_field = Poly(polynomial_order=polynomial_order) * new_field
"[1, M, C, M', C', M'', C'' ..., MC, MM'', MCM'...]"
return new_field