discard lower parameters in decode_counts, example_grover_3 notebook

docs/source/index.rst

@@ -20,6 +20,7 @@ Python and translate them into unitary operators (gates) for use in quantum circ
 
    example_grover_1.ipynb
    example_grover_2.ipynb
+   example_grover_3.ipynb
 
 
 Indices and tables

qlasskit/algorithms/qalgorithm.py

@@ -33,10 +33,8 @@ def oraclize(qf: QlassF, element: Any, name="oracle"):
     if qf.name == name:
         qf.name = f"_{name}"
 
-    oracle = QlassF.from_function(
-        f"def {name}(v: {argt_name}) -> bool:\n   return {qf.name}(v) == {element}",
-        defs=[qf.to_logicfun()],
-    )
+    fs = f"def {name}(v: {argt_name}) -> bool:\n   return {qf.name}(v) == {element}"
+    oracle = QlassF.from_function(fs, defs=[qf.to_logicfun()])
 
     if (
         len(oracle.expressions) == 1

qlasskit/qcircuit/qcircuitwrapper.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
 from .qcircuit import QCircuit, SupportedFramework
 
@@ -63,7 +63,7 @@ def encode_input(self, *qvals):
     def decode_output(self, istr):
         raise Exception("Abstract")
 
-    def decode_counts(self, counts: Dict[str, int]) -> Dict[Any, int]:
+    def decode_counts(self, counts: Dict[str, int], discard_lower: Optional[int] = None) -> Dict[Any, int]:
         """Decode data from a circuit counts dict"""
         outcomes = [(self.decode_output(e), c) for (e, c) in counts.items()]
         int_counts: Dict[Any, int] = {}
@@ -72,6 +72,10 @@ def decode_counts(self, counts: Dict[str, int]) -> Dict[Any, int]:
                 int_counts[e] += c
             else:
                 int_counts[e] = c
+
+        if discard_lower:
+            int_counts = dict(filter(lambda el: el[1] >= discard_lower, int_counts.items()))
+
         return int_counts
 
     def circuit(self):