# MIPLearn: A Machine-Learning Framework for Mixed-Integer Optimization # Copyright (C) 2019-2020 Argonne National Laboratory. All rights reserved. # Written by Alinson S. Xavier import tensorflow as tf import tensorflow.keras as keras from tensorflow.keras.models import Sequential from tensorflow.keras.layers import Dense, Dropout, Flatten, Activation import numpy as np class WarmStartPredictor: def __init__(self, model=None, threshold=0.80): self.model = model self.threshold = threshold def fit(self, train_x, train_y): pass def predict(self, x): if self.model is None: return None assert isinstance(x, np.ndarray) y = self.model.predict(x) n_vars = y.shape[0] ws = np.array([float("nan")] * n_vars) ws[y[:,0] > self.threshold] = 1.0 ws[y[:,1] > self.threshold] = 0.0 return ws