correct sign should be lnZ

hotrg_sweep.py

@@ -100,11 +100,11 @@ if __name__=='__main__':
     
     if args.init == 'hotrg':
         with torch.no_grad():
-            loss = -model.init_isometry(T)
+            lnZ = model.init_isometry(T)
             if args.exact is not None:
-                print ('initial loss with hotrg:', loss.item(), (loss.item()-args.exact)/np.abs(args.exact) )
+                print ('initial loss with hotrg:', -lnZ.item(), (-lnZ.item()-args.exact)/np.abs(args.exact) )
             else:
-                print ('initial loss with hotrg:', sweeps, loss.item() )
+                print ('initial loss with hotrg:', sweeps, -lnZ.item() )
     else:
         pass 
     
@@ -123,9 +123,9 @@ if __name__=='__main__':
         for s in range(args.nstays): # local sweeps
             model.zero_grad()
             start = time.time()
-            loss = -model.forward(T) # loss = -lnZ
+            lnZ = model.forward(T) 
             forward = time.time() 
-            loss.backward()
+            lnZ.backward()
             backward = time.time()
             
             #compute environment from gradient  
@@ -146,7 +146,7 @@ if __name__=='__main__':
             #isometry = model.params[step].view(chi**2, chi_new)
             #ovlp = isometry_last.t()@isometry
             #I = torch.eye(chi_new, dtype=dtype, device=device)
-            #print (step, s, torch.dist(ovlp, I).item(), torch.dist(ovlp, -I).item())
+            #print (step, s, torch.dist(ovlp, I).item())
 
         #print(forward-start, backward - forward, svd-backward)
         step += direction
@@ -155,9 +155,9 @@ if __name__=='__main__':
         if (step==args.niter-1 or step==0):
             direction *= -1
             sweeps += 1
-            loss = -model.forward(T) # loss = -lnZ
+            lnZ = model.forward(T) 
             
             if args.exact is not None:
-                print (sweeps, loss.item(), (loss.item()-args.exact)/np.abs(args.exact) )
+                print (sweeps, -lnZ.item(), (-lnZ.item()-args.exact)/np.abs(args.exact) )
             else:
-                print (sweeps, loss.item())
+                print (sweeps, -lnZ.item())