More fixes

src/QiskitOpt.jl

@@ -40,11 +40,13 @@ function quadratic_program(sampler::QUBODrivers.AbstractSampler{T}) where {T}
     linear    = PythonCall.pydict()
     quadratic = PythonCall.pydict()
 
+    sense = MOI.get(sampler, MOI.ObjectiveSense())
+
     for i in 1:n
-        linear[string(i)] = L[i]
+        linear[string(i)] = L[i] * (sense == MOI.MIN_SENSE ? 1 : -1)
     end
     for i in 1:n, j in 1:n
-        quadratic[string(i), string(j)] = Q[i,j]
+        quadratic[string(i), string(j)] = Q[i,j] * (sense == MOI.MIN_SENSE ? 1 : -1)
     end
 
     qp = qiskit_optimization.QuadraticProgram()
@@ -54,8 +56,8 @@ function quadratic_program(sampler::QUBODrivers.AbstractSampler{T}) where {T}
     end
 
     qp.minimize(linear = linear, quadratic = quadratic)
-
-    return return qp.to_ising()[0]
+    
+    return qp.to_ising()
 end
 
 export  VQE, QAOA

src/VQE.jl

@@ -47,15 +47,15 @@ function QUBODrivers.sample(sampler::Optimizer{T}) where {T}
         "evals"  => Vector{Float64}(),
     )
 
-    retrieve(sampler) do result, sample_results
+    retrieve(sampler) do result, sample_results, qp_offset
 
         for key in sample_results.keys()
             state = reverse(parse.(Int,split(pyconvert.(String, key),"")))
             sample = QUBOTools.Sample{T,Int}(
             # state:
             state,
             # energy:
-            α * (state'* (Q+Diagonal(L)) * state + β),
+            QUBOTools.value(state, L, Q, α, β),
             # reads:
             pyconvert(Int, sample_results[key])
             )   
@@ -111,7 +111,9 @@ function retrieve(
         _backend
     end
 
-    ising_hamiltonian = quadratic_program(sampler)
+    ising_qp = quadratic_program(sampler)
+    ising_hamiltonian = ising_qp[0]
+    qp_offset = ising_qp[1]
     ansatz = ansatz_instance(num_qubits = num_qubits)
 
     # pass manager for the quantum circuit (optimize the circuit for the target device)
@@ -160,7 +162,7 @@ function retrieve(
     sampling_result = qiskit_sampler.run(pylist([optimized_qc])).result()[0]
     samples = sampling_result.data.meas.get_counts()
 
-    callback(result, samples)
+    callback(result, samples, qp_offset)
 
     return nothing
 end