def getpoint_spline(dist, tck):
    x = fs(getlengthfromspline,0.0,(tck,dist))[0]
    return x,interpolate.splev(x,tck,der=0)
	def d_to_x_old(self,length,start_x): #Bad idea! The solver is calling splev more than required.
 		x_l = fs(lambda x: self.x_to_d(start_x,x) - length,self.road_x[0])
		return x_l