@sh.add_function(dsp, outputs=['k_factor_curve'], weight=2)
def default_tc_k_factor_curve():
"""
Returns a default k factor curve for a generic torque converter.
:return:
k factor curve.
:rtype: callable
"""
from co2mpas.defaults import dfl
par = dfl.functions.default_tc_k_factor_curve
a = par.STAND_STILL_TORQUE_RATIO, par.LOCKUP_SPEED_RATIO
return define_k_factor_curve(*a)