Merge pull request #158 from Zhaoyilunnn/master

fix: close #155, close #157

quafu/results/results.py

@@ -2,9 +2,11 @@
 from collections import OrderedDict
 
 import matplotlib.pyplot as plt
+
 from ..algorithms.hamiltonian import Hamiltonian
 from ..utils.basis import *
 
+
 class Result(object):
     """Basis class for quantum results"""
 
@@ -79,12 +81,12 @@ def plot_probabilities(self):
 
 
 class SimuResult(Result):
-    def __init__(self, res_info : dict):
+    def __init__(self, res_info: dict):
         """
         Args:
             res_info: data from simulator
         """
-        self._meta_data  = res_info
+        self._meta_data = res_info
         counts = res_info["counts"]
         if counts:
             if isinstance(list(counts.keys())[0], int):
@@ -97,7 +99,7 @@ def __init__(self, res_info : dict):
 
         self._probabilities = []
 
-    def __getitem__(self, key:str):
+    def __getitem__(self, key: str):
         """
         Get meta_data of simulate results.
         Args:
@@ -111,65 +113,70 @@ def get_statevector(self):
         try:
             return self["statevector"]
         except KeyError:
-            raise KeyError("no statevector saved from %s simulator" %self["simulator"])
-    
+            raise KeyError("no statevector saved from %s simulator" % self["simulator"])
+
     @property
     def probabilities(self):
-        if not self._probabilities:
+        if len(self._probabilities) == 0:
             self.calc_probabilities()
         return self._probabilities
-   
+
     @property
     def counts(self):
-       return self["counts"]
-    
-    def calc_probabilities(self):    
-        psi =  self.get_statevector()
+        return self["counts"]
+
+    def calc_probabilities(self):
+        psi = self.get_statevector()
         num = self["qbitnum"]
         measures = list(self["measures"].keys())
         values_tmp = list(self["measures"].values())
         values = np.argsort(values_tmp)
-
 
         from ..simulators.default_simulator import permutebits, ptrace
+
         psi = permutebits(psi, range(num)[::-1])
         if measures:
             self._probabilities = ptrace(psi, measures)
             self._probabilities = permutebits(self._probabilities, values)
         else:
-            self._probabilities = np.abs(psi)**2
-
-
-    def plot_probabilities(self, full: bool=False, reverse_basis: bool=False, sort:bool=None, from_counts=False):
+            self._probabilities = np.abs(psi) ** 2
+
+    def plot_probabilities(
+        self,
+        full: bool = False,
+        reverse_basis: bool = False,
+        sort: bool = None,
+        from_counts=False,
+    ):
         """
         Plot the probabilites of measured qubits
         """
         import matplotlib.pyplot as plt
+
         if from_counts:
             counts = self._meta_data["counts"]
             total_counts = sum(counts.values())
             probabilities = {}
             for key in self._meta_data["counts"]:
-                probabilities[key] = counts[key]/total_counts
+                probabilities[key] = counts[key] / total_counts
 
-
             bitstrs = list(probabilities.keys())
             probs = list(probabilities.values())
             plt.figure()
-            plt.bar(range(len(probs)), probs, tick_label = bitstrs)
+            plt.bar(range(len(probs)), probs, tick_label=bitstrs)
             plt.xticks(rotation=70)
             plt.ylabel("probabilities")
-            
+
         elif len(self.get_statevector()) > 0:
             if not full:
                 inds = np.where(self.probabilities > 1e-14)[0]
                 probs = self.probabilities[inds]
-            
+
             measures = self._meta_data["measures"]
             num = len(measures) if measures else self["qbitnum"]
-            basis=np.array([bin(i)[2:].zfill(num) for i in inds])
+            basis = np.array([bin(i)[2:].zfill(num) for i in inds])
             if reverse_basis:
-                basis=np.array([bin(i)[2:].zfill(num)[::-1] for i in inds])
+                basis = np.array([bin(i)[2:].zfill(num)[::-1] for i in inds])
 
             if sort == "ascend":
                 orders = np.argsort(probs)
@@ -187,7 +194,6 @@ def plot_probabilities(self, full: bool=False, reverse_basis: bool=False, sort:b
         else:
             raise ValueError("No data for ploting")
 
-
     def calc_density_matrix(self):
         psi = self.get_statevector()
         num = self["qbitnum"]
@@ -198,12 +204,14 @@ def calc_density_matrix(self):
             measures = list(range(num))
             values = list(range(num))
         from ..simulators.default_simulator import permutebits, ptrace
+
         psi = permutebits(psi, range(num)[::-1])
         rho = ptrace(psi, measures, diag=False)
         rho = permutebits(rho, values)
         return rho
 
-#TODO:These should merge to paulis
+
+# TODO:These should merge to paulis
 def intersec(a, b):
     inter = []
     aind = []
@@ -264,4 +272,4 @@ def merge_measure(obslist):
                 measure_basis.append(obs)
                 targ_basis.append(len(measure_basis) - 1)
 
-    return measure_basis, targ_basis
+    return measure_basis, targ_basis