fix #41

Author: refraction-ray

CHANGELOG.md

@@ -40,6 +40,8 @@
 
 - Fix to use `status` for `circuit.sample` when `allow_state=True`.
 
+- Fix sample bug when number of qubit exceeding 32.
+
 ### Changed
 
 - The order of arguments of `tc.timeevol.ed_evol` are changed for consistent interface with other evolution methods.

tensorcircuit/basecircuit.py

@@ -19,7 +19,6 @@
     correlation_from_counts,
     measurement_counts,
     sample_int2bin,
-    sample_bin2int,
     sample2all,
 )
 from .abstractcircuit import AbstractCircuit
@@ -619,8 +618,8 @@ def perfect_sampling(key: Any) -> Any:
             if format is None:
                 return r
             r = backend.stack([ri[0] for ri in r])  # type: ignore
-            r = backend.cast(r, "int32")
-            ch = sample_bin2int(r, self._nqubits)
+            ch = backend.cast(r, "int32")
+            # ch = sample_bin2int(r, self._nqubits)
         else:  # allow_state
             if batch is None:
                 nbatch = 1

tensorcircuit/quantum.py

@@ -9,6 +9,7 @@
 import os
 from functools import partial, reduce
 from operator import matmul, mul, or_
+from collections import Counter
 from typing import (
     Any,
     Callable,
@@ -2886,6 +2887,17 @@ def sample2all(
     :return: measurement results specified as ``format``
     :rtype: Any
     """
+    if n > 32:
+        assert (
+            len(backend.shape_tuple(sample)) == 2
+        ), "n>32 is only supported for ``sample_bin``"
+        if format == "sample_bin":
+            return sample
+        if format == "count_dict_bin":
+            binary_strings = ["".join(map(str, shot)) for shot in sample]
+            return dict(Counter(binary_strings))
+        raise ValueError(f"n={n} is too large for measurement representaion: {format}")
+
     if len(backend.shape_tuple(sample)) == 1:
         sample_int = sample
         sample_bin = sample_int2bin(sample, n)