def test_sum_layer_backprop():
# input layer made of 5 generic nodes
node1 = Node()
node2 = Node()
node3 = Node()
node4 = Node()
node5 = Node()
# top layer made by 3 sum nodes
sum1 = SumNode()
sum2 = SumNode()
sum3 = SumNode()
# linking to input nodes
weight11 = 0.3
sum1.add_child(node1, weight11)
weight12 = 0.3
sum1.add_child(node2, weight12)
weight13 = 0.4
sum1.add_child(node3, weight13)
weight22 = 0.15
sum2.add_child(node2, weight22)
weight23 = 0.15
sum2.add_child(node3, weight23)
weight24 = 0.7
sum2.add_child(node4, weight24)
weight33 = 0.4
sum3.add_child(node3, weight33)
weight34 = 0.25
sum3.add_child(node4, weight34)
weight35 = 0.35
sum3.add_child(node5, weight35)
sum_layer = SumLayer([sum1, sum2, sum3])
# setting input values
val1 = 0.0
node1.set_val(val1)
val2 = 0.5
node2.set_val(val2)
val3 = 0.3
node3.set_val(val3)
val4 = 1.0
node4.set_val(val4)
val5 = 0.0
node5.set_val(val5)
# evaluating
sum_layer.eval()
print('eval\'d layer:', sum_layer.node_values())
# set the parent derivatives
sum_der1 = 1.0
sum1.log_der = log(sum_der1)
sum_der2 = 1.0
sum2.log_der = log(sum_der2)
sum_der3 = 0.0
sum3.log_der = LOG_ZERO
# back prop layer wise
sum_layer.backprop()
# check for correctness
try:
log_der1 = log(sum_der1 * weight11)
except:
log_der1 = LOG_ZERO
try:
log_der2 = log(sum_der1 * weight12 +
sum_der2 * weight22)
except:
log_der2 = LOG_ZERO
try:
log_der3 = log(sum_der1 * weight13 +
sum_der2 * weight23 +
sum_der3 * weight33)
except:
log_der3 = LOG_ZERO
try:
log_der4 = log(sum_der2 * weight24 +
sum_der3 * weight34)
except:
log_der4 = LOG_ZERO
try:
log_der5 = log(sum_der3 * weight35)
except:
log_der5 = LOG_ZERO
# printing, just in case
print('child log der', node1.log_der, node2.log_der,
node3.log_der, node4.log_der, node5.log_der)
print('exact log der', log_der1, log_der2, log_der3,
log_der4, log_der5)
if IS_LOG_ZERO(log_der1):
assert IS_LOG_ZERO(node1.log_der)
else:
assert_almost_equal(log_der1, node1.log_der, 15)
if IS_LOG_ZERO(log_der2):
assert IS_LOG_ZERO(node2.log_der)
else:
assert_almost_equal(log_der2, node2.log_der, 15)
if IS_LOG_ZERO(log_der3):
assert IS_LOG_ZERO(node3.log_der)
else:
assert_almost_equal(log_der3, node3.log_der, 15)
if IS_LOG_ZERO(log_der4):
assert IS_LOG_ZERO(node4.log_der)
else:
assert_almost_equal(log_der4, node4.log_der, 15)
if IS_LOG_ZERO(log_der5):
assert IS_LOG_ZERO(node5.log_der)
else:
assert_almost_equal(log_der5, node5.log_der, 15)
# updating weights
eta = 0.1
sum_layer.update_weights(Spn.test_weight_update, 0)
# checking for correctness
weight_u11 = sum_der1 * val1 * eta + weight11
weight_u12 = sum_der1 * val2 * eta + weight12
weight_u13 = sum_der1 * val3 * eta + weight13
weight_u22 = sum_der2 * val2 * eta + weight22
weight_u23 = sum_der2 * val3 * eta + weight23
weight_u24 = sum_der2 * val4 * eta + weight24
weight_u33 = sum_der3 * val3 * eta + weight33
weight_u34 = sum_der3 * val4 * eta + weight34
weight_u35 = sum_der3 * val5 * eta + weight35
# normalizing
weight_sum1 = weight_u11 + weight_u12 + weight_u13
weight_sum2 = weight_u22 + weight_u23 + weight_u24
weight_sum3 = weight_u33 + weight_u34 + weight_u35
weight_u11 = weight_u11 / weight_sum1
weight_u12 = weight_u12 / weight_sum1
weight_u13 = weight_u13 / weight_sum1
weight_u22 = weight_u22 / weight_sum2
weight_u23 = weight_u23 / weight_sum2
weight_u24 = weight_u24 / weight_sum2
weight_u33 = weight_u33 / weight_sum3
weight_u34 = weight_u34 / weight_sum3
weight_u35 = weight_u35 / weight_sum3
print('expected weights', weight_u11, weight_u12, weight_u13,
weight_u22, weight_u23, weight_u24,
weight_u33, weight_u34, weight_u35)
print('found weights', sum1.weights[0], sum1.weights[1], sum1.weights[2],
sum2.weights[0], sum2.weights[1], sum2.weights[2],
sum3.weights[0], sum3.weights[1], sum3.weights[2])
assert_almost_equal(weight_u11, sum1.weights[0], 10)
assert_almost_equal(weight_u12, sum1.weights[1], 10)
assert_almost_equal(weight_u13, sum1.weights[2], 10)
assert_almost_equal(weight_u22, sum2.weights[0], 10)
assert_almost_equal(weight_u23, sum2.weights[1], 10)
assert_almost_equal(weight_u24, sum2.weights[2], 10)
assert_almost_equal(weight_u33, sum3.weights[0], 10)
assert_almost_equal(weight_u34, sum3.weights[1], 10)
assert_almost_equal(weight_u35, sum3.weights[2], 10)
#
# resetting derivatives
#
node1.log_der = LOG_ZERO
node2.log_der = LOG_ZERO
node3.log_der = LOG_ZERO
node4.log_der = LOG_ZERO
node5.log_der = LOG_ZERO
# setting new values as inputs
val1 = 0.0
node1.set_val(val1)
val2 = 0.0
node2.set_val(val2)
val3 = 0.3
node3.set_val(val3)
val4 = 1.0
node4.set_val(val4)
val5 = 1.0
node5.set_val(val5)
# evaluating again
sum_layer.eval()
print('eval\'d layer:', sum_layer.node_values())
# set the parent derivatives
sum_der1 = 1.0
sum1.log_der = log(sum_der1)
sum_der2 = 1.0
sum2.log_der = log(sum_der2)
sum_der3 = 0.0
sum3.log_der = LOG_ZERO
# back prop layer wise
sum_layer.backprop()
# check for correctness
try:
log_der1 = log(sum_der1 * weight_u11)
except:
log_der1 = LOG_ZERO
try:
log_der2 = log(sum_der1 * weight_u12 +
sum_der2 * weight_u22)
except:
log_der2 = LOG_ZERO
try:
log_der3 = log(sum_der1 * weight_u13 +
sum_der2 * weight_u23 +
sum_der3 * weight_u33)
except:
log_der3 = LOG_ZERO
try:
log_der4 = log(sum_der2 * weight_u24 +
sum_der3 * weight_u34)
except:
log_der4 = LOG_ZERO
try:
log_der5 = log(sum_der3 * weight_u35)
except:
log_der5 = LOG_ZERO
# printing, just in case
print('child log der', node1.log_der, node2.log_der,
node3.log_der, node4.log_der, node5.log_der)
print('exact log der', log_der1, log_der2, log_der3,
log_der4, log_der5)
if IS_LOG_ZERO(log_der1):
assert IS_LOG_ZERO(node1.log_der)
else:
assert_almost_equal(log_der1, node1.log_der, 15)
if IS_LOG_ZERO(log_der2):
assert IS_LOG_ZERO(node2.log_der)
else:
assert_almost_equal(log_der2, node2.log_der, 15)
if IS_LOG_ZERO(log_der3):
assert IS_LOG_ZERO(node3.log_der)
else:
assert_almost_equal(log_der3, node3.log_der, 15)
if IS_LOG_ZERO(log_der4):
assert IS_LOG_ZERO(node4.log_der)
else:
assert_almost_equal(log_der4, node4.log_der, 15)
if IS_LOG_ZERO(log_der5):
assert IS_LOG_ZERO(node5.log_der)
else:
assert_almost_equal(log_der5, node5.log_der, 15)
def test_sum_node_backprop():
# create child nodes
child1 = Node()
val1 = 1.
child1.set_val(val1)
child2 = Node()
val2 = 1.
child2.set_val(val2)
# create sum node and adding children to it
sum_node1 = SumNode()
weight11 = 0.8
weight12 = 0.2
sum_node1.add_child(child1, weight11)
sum_node1.add_child(child2, weight12)
# adding a coparent
sum_node2 = SumNode()
weight21 = 0.6
weight22 = 0.4
sum_node2.add_child(child1, weight21)
sum_node2.add_child(child2, weight22)
# evaluating
sum_node1.eval()
sum_node2.eval()
# setting the log derivatives to the parents
sum_node_der1 = 1.0
sum_node1.log_der = log(sum_node_der1)
sum_node1.backprop()
sum_node_der2 = 1.0
sum_node2.log_der = log(sum_node_der2)
sum_node2.backprop()
# checking for correctness
log_der1 = log(weight11 * sum_node_der1 +
weight21 * sum_node_der2)
log_der2 = log(weight12 * sum_node_der1 +
weight22 * sum_node_der2)
print('log ders 1:{lgd1} 2:{lgd2}'.format(lgd1=log_der1,
lgd2=log_der2))
assert_almost_equal(log_der1, child1.log_der, 15)
assert_almost_equal(log_der2, child2.log_der, 15)
# resetting
child1.log_der = LOG_ZERO
child2.log_der = LOG_ZERO
# now changing the initial der values
sum_node_der1 = 0.5
sum_node1.log_der = log(sum_node_der1)
sum_node1.backprop()
sum_node_der2 = 0.0
sum_node2.log_der = LOG_ZERO
sum_node2.backprop()
# checking for correctness
log_der1 = log(weight11 * sum_node_der1 +
weight21 * sum_node_der2)
log_der2 = log(weight12 * sum_node_der1 +
weight22 * sum_node_der2)
print('log ders 1:{lgd1} 2:{lgd2}'.format(lgd1=log_der1,
lgd2=log_der2))
assert_almost_equal(log_der1, child1.log_der, 15)
assert_almost_equal(log_der2, child2.log_der, 15)