better localization update with amcl or odom

edit

Hi. I am running a differential robot. In my original code i use encoder information for odom update. Can i use amcl_pose to update odom information ?

I cant decide whether to use encoder information or amcl_pose for better localization.

Original Code

self.dth = self.vth * dt
    self.pth += self.dth
    if(self.pth >= two_pi):
        self.pth-= two_pi
    if(self.pth <= -two_pi):
        self.pth += two_pi

    self.vxx= self.vx * math.cos(self.vth)
    self.vxy= (self.vx * math.sin(self.vth))


    self.dx = (self.vxx * math.cos(self.pth)-self.vxy*sin(self.pth)) * dt    
    self.dy = (self.vxx * math.sin(self.pth)+ self.vxy*cos(self.pth)) * dt     

    self.px += self.dx            #last position
    self.py += self.dy       

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Update code with Amcl
I add 3 line to update position info


 self.px=amcl_pose1.pose.pose.position.x
    self.py=amcl_pose1.pose.pose.position.y
    self.pth=amcl_pose1.pose.pose.orientation.z 

   self.dth = self.vth * dt
    self.pth += self.dth
    if(self.pth >= two_pi):
        self.pth-= two_pi
    if(self.pth <= -two_pi):
        self.pth += two_pi

    self.vxx= self.vx * math.cos(self.vth)
    self.vxy= (self.vx * math.sin(self.vth))


    self.dx = (self.vxx * math.cos(self.pth)-self.vxy*sin(self.pth)) * dt    
    self.dy = (self.vxx * math.sin(self.pth)+ self.vxy*cos(self.pth)) * dt 



self.px += self.dx            #last position
self.py += self.dy