def prepareANNDataset(data, prob=None):
'''
Method to prepare the dataset for ANN training
and testing
'''
# we only import this when preparing ANN dataset
import pybrain.datasets as dt
# supplementary method to convert list to tuple
def extract(row):
return tuple(row)
# get the number of inputs and outputs
inputs = len(data[0].columns)
outputs = len(data[1].axes) + 1
if prob == 'regression':
outputs -= 1
# create dataset object
dataset = dt.SupervisedDataSet(inputs, outputs)
# convert dataframes to lists of tuples
x = list(data[0].apply(extract, axis=1))
if prob == 'regression':
y = [(item) for item in data[1]]
else:
y = [(item, abs(item - 1)) for item in data[1]]
# and add samples to the ANN dataset
for x_item, y_item in zip(x, y):
dataset.addSample(x_item, y_item)
return dataset
def nnreal(x, y, hidden=5000, threshold=.1, numwords=10):
sums = np.sum(y, axis=0).tolist()
mostcommonwords = [
j[0] for j in sorted(enumerate(sums), key=lambda i: i[1], reverse=True)
[:numwords]
]
# x = x[lag:]
# y = y[:len(x)]
x, y = nonzero(x, y)
numInputFeatures, numOutputFeatures = x.shape[1], y.shape[1]
ds = pbds.SupervisedDataSet(numInputFeatures, numOutputFeatures)
ds.setField('input', x)
ds.setField('target', y)
dstrain, dstest = ds.splitWithProportion(.93)
nn = pbts.buildNetwork(numInputFeatures,
hidden,
numOutputFeatures,
bias=True)
trainer = pbsvt.BackpropTrainer(nn, dstrain)
errors = []
e = 1
i = 0
while e > .1 and i < 50:
e = trainer.train()
print e
i += 1
def train_nn(net, train_data, train_labels):
ntrain = len(train_data)
train_dataset = pd.SupervisedDataSet(indim, outdim)
for index in range(ntrain):
train_dataset.addSample(train_data[index], train_labels[index])
trainer = BackpropTrainer(net, train_dataset)
train_error = trainer.train()
return net, train_error
def __init__(self, input_size, topology):
topology = list(topology) + [1]
self._net = _shortcuts.buildNetwork(
*([input_size] + topology
)) #This is used because buildNetwork expects many arguments
self._data = _datasets.SupervisedDataSet(topology[0], topology[-1])
self._data_source = {'inp': _np.array([]), 'tar': _np.array([])}
self._samples_limit = None
new_params = _np.array([1. / input_size] * len(self._net.params))
self._net._setParameters(new_params)
self._net.sortModules()
def neural_net(self, extrapolation_spots, data):
net = buildNetwork(2, 10, 1)
ds = pd.SupervisedDataSet(2, 1)
for row in self.sample_data:
ds.addSample((row[0], row[1]), (row[2], ))
trainer = BackpropTrainer(net, ds)
trainer.trainUntilConvergence()
new_points = np.zeros((len(extrapolation_spots), 3))
new_points[:, 0] = extrapolation_spots[:, 0]
new_points[:, 1] = extrapolation_spots[:, 1]
for i in range(len(extrapolation_spots)):
new_points[i, 2] = net.activate(extrapolation_spots[i, :2])
combined = np.concatenate((data, new_points))
return combined
def to_supervised_dataset(list, target):
super = ds.SupervisedDataSet(len(list[0]), 1)
for l in enumerate(list):
super.addSample(l, target)
