ArcLoss

https://github.com/yanchangqin/Centrloss-ArcLoss/blob/master/ArcLoss.py
 

  

   

    

     

    
    

     

      class Arc_Loss(nn.Module):
     
    
   

    

     

    
    

     
 def __init__(self,feature_num,cls_num,m =0.1,s=64):
     
    
   

    

     

    
    

     

       super().__init__()
     
    
   

    

     

    
    

     

       self.s = s
     
    
   

    

     

    
    

     

       self.m = m
     
    
   

    

     

    
    

     

       self.W=nn.Parameter(torch.randn(feature_num,cls_num))
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 def forward(self, feature):
     
    
   

    

     

    
    

     

       _w = F.normalize(self.W,dim=0)
     
    
   

    

     

    
    

     

       _x = F.normalize(feature,dim=1)
     
    
   

    

     

    
    

     

       cosa = (torch.matmul(_x,_w)/10)
     
    
   

    

     

    
    

     

       a = torch.acos(cosa)
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       top = torch.exp(torch.cos(a+self.m)*self.s)
     
    
   

    

     

    
    

     

       _top = torch.exp(torch.cos(a)*self.s)
     
    
   

    

     

    
    

     

       bottom = torch.sum(_top,dim=1,keepdim=True)
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 # sina = torch.sqrt(1-torch.pow(cosa,2))
     
    
   

    

     

    
    

     
 # cosm = torch.cos(torch.tensor(self.m)).cuda()
     
    
   

    

     

    
    

     
 # sinm = torch.cos(torch.tensor(self.m)).cuda()
     
    
   

    

     

    
    

     
 # cosa_m =cosa*cosm-sina*sinm
     
    
   

    

     

    
    

     
 # top =torch.exp(cosa_m*sel
     
    
  
 

文章来源: blog.csdn.net，作者：网奇，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/jacke121/article/details/103811042