TN1D: utilize standard canonize/compress funcs, test new compression …

…methods

quimb/tensor/tensor_1d.py

@@ -33,12 +33,13 @@
 )
 from .tensor_core import (
     Tensor,
-    TensorNetwork,
     bonds,
     new_bond,
     oset,
     rand_uuid,
     tags_to_oset,
+    tensor_canonize_bond,
+    tensor_compress_bond,
 )
 
 align_TN_1D = deprecated(
@@ -681,42 +682,6 @@ class TensorNetwork1DFlat(TensorNetwork1D):
 
     _EXTRA_PROPS = ("_site_tag_id", "_L")
 
-    def _left_decomp_site(self, i, bra=None, **split_opts):
-        T1, T2 = self[i], self[i + 1]
-        rix, lix = T1.filter_bonds(T2)
-
-        set_default_compress_mode(split_opts, self.cyclic)
-        Q, R = T1.split(lix, get="tensors", right_inds=rix, **split_opts)
-        R = R @ T2
-
-        Q.transpose_like_(T1)
-        R.transpose_like_(T2)
-
-        self[i].modify(data=Q.data)
-        self[i + 1].modify(data=R.data)
-
-        if bra is not None:
-            bra[i].modify(data=Q.data.conj())
-            bra[i + 1].modify(data=R.data.conj())
-
-    def _right_decomp_site(self, i, bra=None, **split_opts):
-        T1, T2 = self[i], self[i - 1]
-        lix, rix = T1.filter_bonds(T2)
-
-        set_default_compress_mode(split_opts, self.cyclic)
-        L, Q = T1.split(lix, get="tensors", right_inds=rix, **split_opts)
-        L = T2 @ L
-
-        L.transpose_like_(T2)
-        Q.transpose_like_(T1)
-
-        self[i - 1].modify(data=L.data)
-        self[i].modify(data=Q.data)
-
-        if bra is not None:
-            bra[i - 1].modify(data=L.data.conj())
-            bra[i].modify(data=Q.data.conj())
-
     def left_canonize_site(self, i, bra=None):
         r"""Left canonize this TN's ith site, inplace::
 
@@ -732,7 +697,11 @@ def left_canonize_site(self, i, bra=None):
         bra : None or matching TensorNetwork to self, optional
             If set, also update this TN's data with the conjugate canonization.
         """
-        self._left_decomp_site(i, bra=bra, method="qr")
+        tl, tr = self[i], self[i + 1]
+        tensor_canonize_bond(tl, tr)
+        if bra is not None:
+            bra[i].modify(data=conj(tl.data))
+            bra[i + 1].modify(data=conj(tr.data))
 
     def right_canonize_site(self, i, bra=None):
         r"""Right canonize this TN's ith site, inplace::
@@ -749,7 +718,11 @@ def right_canonize_site(self, i, bra=None):
          bra : None or matching TensorNetwork to self, optional
             If set, also update this TN's data with the conjugate canonization.
         """
-        self._right_decomp_site(i, bra=bra, method="lq")
+        tl, tr = self[i - 1], self[i]
+        tensor_canonize_bond(tr, tl)
+        if bra is not None:
+            bra[i].modify(data=conj(tr.data))
+            bra[i - 1].modify(data=conj(tl.data))
 
     def left_canonize(self, stop=None, start=None, normalize=False, bra=None):
         r"""Left canonize all or a portion of this TN. If this is a MPS,
@@ -981,8 +954,17 @@ def left_compress_site(self, i, bra=None, **compress_opts):
         compress_opts
             Supplied to :meth:`Tensor.split`.
         """
+        set_default_compress_mode(compress_opts, self.cyclic)
         compress_opts.setdefault("absorb", "right")
-        self._left_decomp_site(i, bra=bra, **compress_opts)
+        compress_opts.setdefault("reduced", "left")
+
+        tl, tr = self[i], self[i + 1]
+        tensor_compress_bond(tl, tr, **compress_opts)
+
+        if bra is not None:
+            bra[i].modify(data=conj(tl.data))
+            bra[i + 1].modify(data=conj(tr.data))
+
 
     def right_compress_site(self, i, bra=None, **compress_opts):
         """Right compress this 1D TN's ith site, such that the site is then
@@ -997,8 +979,16 @@ def right_compress_site(self, i, bra=None, **compress_opts):
         compress_opts
             Supplied to :meth:`Tensor.split`.
         """
+        set_default_compress_mode(compress_opts, self.cyclic)
         compress_opts.setdefault("absorb", "left")
-        self._right_decomp_site(i, bra=bra, **compress_opts)
+        compress_opts.setdefault("reduced", "right")
+
+        tl, tr = self[i - 1], self[i]
+        tensor_compress_bond(tl, tr, **compress_opts)
+
+        if bra is not None:
+            bra[i].modify(data=conj(tr.data))
+            bra[i - 1].modify(data=conj(tl.data))
 
     def left_compress(self, start=None, stop=None, bra=None, **compress_opts):
         """Compress this 1D TN, from left to right, such that it becomes
@@ -1066,13 +1056,19 @@ def compress(self, form=None, **compress_opts):
             form = "right"
 
         if isinstance(form, Integral):
-            self.right_canonize()
-            self.left_compress(**compress_opts)
-            self.right_canonize(stop=form)
+            if form < self.L // 2:
+                self.left_canonize()
+                self.right_compress(**compress_opts)
+                self.left_canonize(stop=form)
+            else:
+                self.right_canonize()
+                self.left_compress(**compress_opts)
+                self.right_canonize(stop=form)
 
         elif form == "left":
             self.right_canonize(bra=compress_opts.get("bra", None))
             self.left_compress(**compress_opts)
+
         elif form == "right":
             self.left_canonize(bra=compress_opts.get("bra", None))
             self.right_compress(**compress_opts)
@@ -1841,7 +1837,7 @@ def gate_with_auto_swap(
             cur_orthog = (i + 1, i + 2)
 
         # make sure sites are orthog center, then apply and split
-        mps.canonize((i, i + 1), cur_orthog)
+        mps.canonize((i, i + 1), cur_orthog=cur_orthog)
         mps.gate_split_(
             G, where=(i + 1, i) if need2flip else (i, i + 1), **compress_opts
         )