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from __future__ import division
import math
import tensorflow as tf
from mi_gru_cell import MiGRUCell
from mi_lstm_cell import MiLSTMCell
from config import config
eps = 1e-20
inf = 1e30
####################################### variables ########################################
'''
Initializes a weight matrix variable given a shape and a name.
Uses random_normal initialization if 1d, otherwise uses xavier.
'''
def getWeight(shape, name = ""):
with tf.variable_scope("weights"):
initializer = tf.contrib.layers.xavier_initializer()
# if len(shape) == 1: # good?
# initializer = tf.random_normal_initializer()
W = tf.get_variable("weight" + name, shape = shape, initializer = initializer)
return W
'''
Initializes a weight matrix variable given a shape and a name. Uses xavier
'''
def getKernel(shape, name = ""):
with tf.variable_scope("kernels"):
initializer = tf.contrib.layers.xavier_initializer()
W = tf.get_variable("kernel" + name, shape = shape, initializer = initializer)
return W
'''
Initializes a bias variable given a shape and a name.
'''
def getBias(shape, name = ""):
with tf.variable_scope("biases"):
initializer = tf.zeros_initializer()
b = tf.get_variable("bias" + name, shape = shape, initializer = initializer)
return b
######################################### basics #########################################
'''
Multiplies input inp of any depth by a 2d weight matrix.
'''
# switch with conv 1?
def multiply(inp, W):
inDim = tf.shape(W)[0]
outDim = tf.shape(W)[1]
newDims = tf.concat([tf.shape(inp)[:-1], tf.fill((1,), outDim)], axis = 0)
inp = tf.reshape(inp, (-1, inDim))
output = tf.matmul(inp, W)
output = tf.reshape(output, newDims)
return output
'''
Concatenates x and y. Support broadcasting.
Optionally concatenate multiplication of x * y
'''
def concat(x, y, dim, mul = False, extendY = False):
if extendY:
y = tf.expand_dims(y, axis = -2)
# broadcasting to have the same shape
y = tf.zeros_like(x) + y
if mul:
out = tf.concat([x, y, x * y], axis = -1)
dim *= 3
else:
out = tf.concat([x, y], axis = -1)
dim *= 2
return out, dim
'''
Adds L2 regularization for weight and kernel variables.
'''
# add l2 in the tf way
def L2RegularizationOp(l2 = None):
if l2 is None:
l2 = config.l2
l2Loss = 0
names = ["weight", "kernel"]
for var in tf.trainable_variables():
if any((name in var.name.lower()) for name in names):
l2Loss += tf.nn.l2_loss(var)
return l2 * l2Loss
######################################### attention #########################################
'''
Transform vectors to scalar logits.
Args:
interactions: input vectors
[batchSize, N, dim]
dim: dimension of input vectors
sumMod: LIN for linear transformation to scalars.
SUM to sum up vectors entries to get scalar logit.
dropout: dropout value over inputs (for linear case)
Return matching scalar for each interaction.
[batchSize, N]
'''
sumMod = ["LIN", "SUM"]
def inter2logits(interactions, dim, sumMod = "LIN", dropout = 1.0, name = "", reuse = None):
with tf.variable_scope("inter2logits" + name, reuse = reuse):
if sumMod == "SUM":
logits = tf.reduce_sum(interactions, axis = -1)
else: # "LIN"
logits = linear(interactions, dim, 1, dropout = dropout, name = "logits")
return logits
'''
Transforms vectors to probability distribution.
Calls inter2logits and then softmax over these.
Args:
interactions: input vectors
[batchSize, N, dim]
dim: dimension of input vectors
sumMod: LIN for linear transformation to scalars.
SUM to sum up vectors entries to get scalar logit.
dropout: dropout value over inputs (for linear case)
Return attention distribution over interactions.
[batchSize, N]
'''
def inter2att(interactions, dim, dropout = 1.0, name = "", reuse = None):
with tf.variable_scope("inter2att" + name, reuse = reuse):
logits = inter2logits(interactions, dim, dropout = dropout)
attention = tf.nn.softmax(logits)
return attention
'''
Sums up features using attention distribution to get a weighted average over them.
'''
def att2Smry(attention, features):
return tf.reduce_sum(tf.expand_dims(attention, axis = -1) * features, axis = -2)
####################################### activations ########################################
'''
Performs a variant of ReLU based on config.relu
PRM for PReLU
ELU for ELU
LKY for Leaky ReLU
otherwise, standard ReLU
'''
def relu(inp):
if config.relu == "PRM":
with tf.variable_scope(None, default_name = "prelu"):
alpha = tf.get_variable("alpha", shape = inp.get_shape()[-1],
initializer = tf.constant_initializer(0.25))
pos = tf.nn.relu(inp)
neg = - (alpha * tf.nn.relu(-inp))
output = pos + neg
elif config.relu == "ELU":
output = tf.nn.elu(inp)
# elif config.relu == "SELU":
# output = tf.nn.selu(inp)
elif config.relu == "LKY":
# output = tf.nn.leaky_relu(inp, config.reluAlpha)
output = tf.maximum(inp, config.reluAlpha * inp)
elif config.relu == "STD": # STD
output = tf.nn.relu(inp)
return output
activations = {
"NON": tf.identity, # lambda inp: inp
"TANH": tf.tanh,
"SIGMOID": tf.sigmoid,
"RELU": relu,
"ELU": tf.nn.elu
}
# Sample from Gumbel(0, 1)
def sampleGumbel(shape):
U = tf.random_uniform(shape, minval = 0, maxval = 1)
return -tf.log(-tf.log(U + eps) + eps)
# Draw a clevr_sample from the Gumbel-Softmax distribution
def gumbelSoftmaxSample(logits, temperature):
y = logits + sampleGumbel(tf.shape(logits))
return tf.nn.softmax(y / temperature)
def gumbelSoftmax(logits, temperature, train): # hard = False
# Sample from the Gumbel-Softmax distribution and optionally discretize.
# Args:
# logits: [batch_size, n_class] unnormalized log-probs
# temperature: non-negative scalar
# hard: if True, take argmax, but differentiate w.r.t. soft clevr_sample y
# Returns:
# [batch_size, n_class] clevr_sample from the Gumbel-Softmax distribution.
# If hard=True, then the returned clevr_sample will be one-hot, otherwise it will
# be a probabilitiy distribution that sums to 1 across classes
y = gumbelSoftmaxSample(logits, temperature)
# k = tf.shape(logits)[-1]
# yHard = tf.cast(tf.one_hot(tf.argmax(y,1),k), y.dtype)
yHard = tf.cast(tf.equal(y, tf.reduce_max(y, 1, keep_dims = True)), y.dtype)
yNew = tf.stop_gradient(yHard - y) + y
if config.gumbelSoftmaxBoth:
return y
if config.gumbelArgmaxBoth:
return yNew
ret = tf.cond(train, lambda: y, lambda: yNew)
return ret
def softmaxDiscrete(logits, temperature, train):
if config.gumbelSoftmax:
return gumbelSoftmax(logits, temperature = temperature, train = train)
else:
return tf.nn.softmax(logits)
def parametricDropout(name, train):
var = tf.get_variable("varDp" + name, shape = (), initializer = tf.constant_initializer(2),
dtype = tf.float32)
dropout = tf.cond(train, lambda: tf.sigmoid(var), lambda: 1.0)
return dropout
###################################### sequence helpers ######################################
'''
Casts exponential mask over a sequence with sequence length.
Used to prepare logits before softmax.
'''
def expMask(seq, seqLength):
maxLength = tf.shape(seq)[-1]
mask = (1 - tf.cast(tf.sequence_mask(seqLength, maxLength), tf.float32)) * (-inf)
masked = seq + mask
return masked
'''
Computes seq2seq loss between logits and target sequences, with given lengths.
'''
def seq2SeqLoss(logits, targets, lengths):
mask = tf.sequence_mask(lengths, maxlen = tf.shape(targets)[1])
loss = tf.contrib.seq2seq.sequence_loss(logits, targets, tf.to_float(mask))
return loss
'''
Computes seq2seq loss between logits and target sequences, with given lengths.
acc1: accuracy per symbol
acc2: accuracy per sequence
'''
def seq2seqAcc(preds, targets, lengths):
mask = tf.sequence_mask(lengths, maxlen = tf.shape(targets)[1])
corrects = tf.logical_and(tf.equal(preds, targets), mask)
numCorrects = tf.reduce_sum(tf.to_int32(corrects), axis = 1)
acc1 = tf.to_float(numCorrects) / (tf.to_float(lengths) + eps) # add small eps instead?
acc1 = tf.reduce_mean(acc1)
acc2 = tf.to_float(tf.equal(numCorrects, lengths))
acc2 = tf.reduce_mean(acc2)
return acc1, acc2
########################################### linear ###########################################
'''
linear transformation.
Args:
inp: input to transform
inDim: input dimension
outDim: output dimension
dropout: dropout over input
batchNorm: if not None, applies batch normalization to inputs
addBias: True to add bias
bias: initial bias value
act: if not None, activation to use after linear transformation
actLayer: if True and act is not None, applies another linear transformation on top of previous
actDropout: dropout to apply in the optional second linear transformation
retVars: if True, return parameters (weight and bias)
Returns linear transformation result.
'''
# batchNorm = {"decay": float, "train": Tensor}
# actLayer: if activation is not non, stack another linear layer
# maybe change naming scheme such that if name = "" than use it as default_name (-->unique?)
def linear(inp, inDim, outDim, dropout = 1.0,
batchNorm = None, addBias = True, bias = 0.0,
act = "NON", actLayer = True, actDropout = 1.0,
retVars = False, name = "", reuse = None):
with tf.variable_scope("linearLayer" + name, reuse = reuse):
W = getWeight((inDim, outDim) if outDim > 1 else (inDim, ))
b = getBias((outDim, ) if outDim > 1 else ()) + bias
if batchNorm is not None:
inp = tf.contrib.layers.batch_norm(inp, decay = batchNorm["decay"],
center = True, scale = True, is_training = batchNorm["train"], updates_collections = None)
# tf.layers.batch_normalization, axis -1 ?
inp = tf.nn.dropout(inp, dropout)
if outDim > 1:
output = multiply(inp, W)
else:
output = tf.reduce_sum(inp * W, axis = -1)
if addBias:
output += b
output = activations[act](output)
# good?
if act != "NON" and actLayer:
output = linear(output, outDim, outDim, dropout = actDropout, batchNorm = batchNorm,
addBias = addBias, act = "NON", actLayer = False,
name = name + "_2", reuse = reuse)
if retVars:
return (output, (W, b))
return output
'''
Computes Multi-layer feed-forward network.
Args:
features: input features
dims: list with dimensions of network.
First dimension is of the inputs, final is of the outputs.
batchNorm: if not None, applies batchNorm
dropout: dropout value to apply for each layer
act: activation to apply between layers.
NON, TANH, SIGMOID, RELU, ELU
'''
# no activation after last layer
# batchNorm = {"decay": float, "train": Tensor}
def FCLayer(features, dims, batchNorm = None, dropout = 1.0, act = "RELU"):
layersNum = len(dims) - 1
for i in range(layersNum):
features = linear(features, dims[i], dims[i+1], name = "fc_%d" % i,
batchNorm = batchNorm, dropout = dropout)
# not the last layer
if i < layersNum - 1:
features = activations[act](features)
return features
###################################### cnns ######################################
'''
Computes convolution.
Args:
inp: input features
inDim: input dimension
outDim: output dimension
batchNorm: if not None, applies batchNorm on inputs
dropout: dropout value to apply on inputs
addBias: True to add bias
kernelSize: kernel size
stride: stride size
act: activation to apply on outputs
NON, TANH, SIGMOID, RELU, ELU
'''
# batchNorm = {"decay": float, "train": Tensor, "center": bool, "scale": bool}
# collections.namedtuple("batchNorm", ("decay", "train"))
def cnn(inp, inDim, outDim, batchNorm = None, dropout = 1.0, addBias = True,
kernelSize = None, stride = 1, act = "NON", name = "", reuse = None):
with tf.variable_scope("cnnLayer" + name, reuse = reuse):
if kernelSize is None:
kernelSize = config.stemKernelSize
kernelH = kernelW = kernelSize
kernel = getKernel((kernelH, kernelW, inDim, outDim))
b = getBias((outDim, ))
if batchNorm is not None:
inp = tf.contrib.layers.batch_norm(inp, decay = batchNorm["decay"], center = batchNorm["center"],
scale = batchNorm["scale"], is_training = batchNorm["train"], updates_collections = None)
inp = tf.nn.dropout(inp, dropout)
output = tf.nn.conv2d(inp, filter = kernel, strides = [1, stride, stride, 1], padding = "SAME")
if addBias:
output += b
output = activations[act](output)
return output
'''
Computes Multi-layer convolutional network.
Args:
features: input features
dims: list with dimensions of network.
First dimension is of the inputs. Final is of the outputs.
batchNorm: if not None, applies batchNorm
dropout: dropout value to apply for each layer
kernelSizes: list of kernel sizes for each layer. Default to config.stemKernelSize
strides: list of strides for each layer. Default to 1.
act: activation to apply between layers.
NON, TANH, SIGMOID, RELU, ELU
'''
# batchNorm = {"decay": float, "train": Tensor, "center": bool, "scale": bool}
# activation after last layer
def CNNLayer(features, dims, batchNorm = None, dropout = 1.0,
kernelSizes = None, strides = None, act = "RELU"):
layersNum = len(dims) - 1
if kernelSizes is None:
kernelSizes = [config.stemKernelSize for i in range(layersNum)]
if strides is None:
strides = [1 for i in range(layersNum)]
for i in range(layersNum):
features = cnn(features, dims[i], dims[i+1], name = "cnn_%d" % i, batchNorm = batchNorm,
dropout = dropout, kernelSize = kernelSizes[i], stride = strides[i], act = act)
return features
######################################## location ########################################
'''
Computes linear positional encoding for h x w grid.
If outDim positive, casts positions to that dimension.
'''
# ignores dim
# h,w can be tensor scalars
def locationL(h, w, dim, outDim = -1, addBias = True):
dim = 2
grid = tf.stack(tf.meshgrid(tf.linspace(-config.locationBias, config.locationBias, w),
tf.linspace(-config.locationBias, config.locationBias, h)), axis = -1)
if outDim > 0:
grid = linear(grid, dim, outDim, addBias = addBias, name = "locationL")
dim = outDim
return grid, dim
'''
Computes sin/cos positional encoding for h x w x (4*dim).
If outDim positive, casts positions to that dimension.
Based on positional encoding presented in "Attention is all you need"
'''
# dim % 4 = 0
# h,w can be tensor scalars
def locationPE(h, w, dim, outDim = -1, addBias = True):
x = tf.expand_dims(tf.to_float(tf.linspace(-config.locationBias, config.locationBias, w)), axis = -1)
y = tf.expand_dims(tf.to_float(tf.linspace(-config.locationBias, config.locationBias, h)), axis = -1)
i = tf.expand_dims(tf.to_float(tf.range(dim)), axis = 0)
peSinX = tf.sin(x / (tf.pow(10000.0, i / dim)))
peCosX = tf.cos(x / (tf.pow(10000.0, i / dim)))
peSinY = tf.sin(y / (tf.pow(10000.0, i / dim)))
peCosY = tf.cos(y / (tf.pow(10000.0, i / dim)))
peSinX = tf.tile(tf.expand_dims(peSinX, axis = 0), [h, 1, 1])
peCosX = tf.tile(tf.expand_dims(peCosX, axis = 0), [h, 1, 1])
peSinY = tf.tile(tf.expand_dims(peSinY, axis = 1), [1, w, 1])
peCosY = tf.tile(tf.expand_dims(peCosY, axis = 1), [1, w, 1])
grid = tf.concat([peSinX, peCosX, peSinY, peCosY], axis = -1)
dim *= 4
if outDim > 0:
grid = linear(grid, dim, outDim, addBias = addBias, name = "locationPE")
dim = outDim
return grid, dim
locations = {
"L": locationL,
"PE": locationPE
}
'''
Adds positional encoding to features. May ease spatial reasoning.
(although not used in the default model).
Args:
features: features to add position encoding to.
[batchSize, h, w, c]
inDim: number of features' channels
lDim: dimension for positional encodings
outDim: if positive, cast enhanced features (with positions) to that dimension
h: features' height
w: features' width
locType: L for linear encoding, PE for cos/sin based positional encoding
mod: way to add positional encoding: concatenation (CNCT), addition (ADD),
multiplication (MUL), linear transformation (LIN).
'''
mods = ["CNCT", "ADD", "LIN", "MUL"]
# if outDim = -1, then will be set based on inDim, lDim
def addLocation(features, inDim, lDim, outDim = -1, h = None, w = None,
locType = "L", mod = "CNCT", name = "", reuse = None): # h,w not needed
with tf.variable_scope("addLocation" + name, reuse = reuse):
batchSize = tf.shape(features)[0]
if h is None:
h = tf.shape(features)[1]
if w is None:
w = tf.shape(features)[2]
dim = inDim
if mod == "LIN":
if outDim < 0:
outDim = dim
grid, _ = locations[locType](h, w, lDim, outDim = outDim, addBias = False)
features = linear(features, dim, outDim, name = "LIN")
features += grid
return features, outDim
if mod == "CNCT":
grid, lDim = locations[locType](h, w, lDim)
# grid = tf.zeros_like(features) + grid
grid = tf.tile(tf.expand_dims(grid, axis = 0), [batchSize, 1, 1, 1])
features = tf.concat([features, grid], axis = -1)
dim += lDim
elif mod == "ADD":
grid, _ = locations[locType](h, w, lDim, outDim = dim)
features += grid
elif mod == "MUL": # MUL
grid, _ = locations[locType](h, w, lDim, outDim = dim)
if outDim < 0:
outDim = dim
grid = tf.tile(tf.expand_dims(grid, axis = 0), [batchSize, 1, 1, 1])
features = tf.concat([features, grid, features * grid], axis = -1)
dim *= 3
if outDim > 0:
features = linear(features, dim, outDim)
dim = outDim
return features, dim
# config.locationAwareEnd
# H, W, _ = config.imageDims
# projDim = config.stemProjDim
# k = config.stemProjPooling
# projDim on inDim or on out
# inDim = tf.shape(features)[3]
'''
Linearize 2d image to linear vector.
Args:
features: batch of 2d images.
[batchSize, h, w, inDim]
h: image height
w: image width
inDim: number of channels
projDim: if not None, project image to that dimension before linearization
outDim: if not None, project image to that dimension after linearization
loc: if not None, add positional encoding:
locType: L for linear encoding, PE for cos/sin based positional encoding
mod: way to add positional encoding: concatenation (CNCT), addition (ADD),
multiplication (MUL), linear transformation (LIN).
pooling: number to pool image with before linearization.
Returns linearized image:
[batchSize, outDim] (or [batchSize, (h / pooling) * (w /pooling) * projDim] if outDim not supported)
'''
# loc = {"locType": str, "mod": str}
def linearizeFeatures(features, h, w, inDim, projDim = None, outDim = None,
loc = None, pooling = None):
if pooling is None:
pooling = config.imageLinPool
if loc is not None:
features = addLocation(features, inDim, lDim = inDim, outDim = inDim,
locType = loc["locType"], mod = loc["mod"])
if projDim is not None:
features = linear(features, dim, projDim)
features = relu(features)
dim = projDim
if pooling > 1:
poolingDims = [1, pooling, pooling, 1]
features = tf.nn.max_pool(features, ksize = poolingDims, strides = poolingDims,
padding = "SAME")
h /= pooling
w /= pooling
dim = h * w * dim
features = tf.reshape(features, (-1, dim))
if outDim is not None:
features = linear(features, dim, outDim)
dim = outDim
return features, dim
################################### multiplication ###################################
# specific dim / proj for x / y
'''
"Enhanced" hadamard product between x and y:
1. Supports optional projection of x, and y prior to multiplication.
2. Computes simple multiplication, or a parametrized one, using diagonal of complete matrix (bi-linear)
3. Optionally concatenate x or y or their projection to the multiplication result.
Support broadcasting
Args:
x: left-hand side argument
[batchSize, dim]
y: right-hand side argument
[batchSize, dim]
dim: input dimension of x and y
dropout: dropout value to apply on x and y
proj: if not None, project x and y:
dim: projection dimension
shared: use same projection for x and y
dropout: dropout to apply to x and y if projected
interMod: multiplication type:
"MUL": x * y
"DIAG": x * W * y for a learned diagonal parameter W
"BL": x' W y for a learned matrix W
concat: if not None, concatenate x or y or their projection.
mulBias: optional bias to stabilize multiplication (x * bias) (y * bias)
Returns the multiplication result
[batchSize, outDim] when outDim depends on the use of proj and cocnat arguments.
'''
# proj = {"dim": int, "shared": bool, "dropout": float} # "act": str, "actDropout": float
## interMod = ["direct", "scalarW", "bilinear"] # "additive"
# interMod = ["MUL", "DIAG", "BL", "ADD"]
# concat = {"x": bool, "y": bool, "proj": bool}
def mul(x, y, dim, dropout = 1.0, proj = None, interMod = "MUL", concat = None, mulBias = None,
extendY = True, name = "", reuse = None):
with tf.variable_scope("mul" + name, reuse = reuse):
origVals = {"x": x, "y": y, "dim": dim}
x = tf.nn.dropout(x, dropout)
y = tf.nn.dropout(y, dropout)
# projection
if proj is not None:
x = tf.nn.dropout(x, proj.get("dropout", 1.0))
y = tf.nn.dropout(y, proj.get("dropout", 1.0))
if proj["shared"]:
xName, xReuse = "proj", None
yName, yReuse = "proj", True
else:
xName, xReuse = "projX", None
yName, yReuse = "projY", None
x = linear(x, dim, proj["dim"], name = xName, reuse = xReuse)
y = linear(y, dim, proj["dim"], name = yName, reuse = yReuse)
dim = proj["dim"]
projVals = {"x": x, "y": y, "dim": dim}
proj["x"], proj["y"] = x, y
if extendY:
y = tf.expand_dims(y, axis = -2)
# broadcasting to have the same shape
y = tf.zeros_like(x) + y
# multiplication
if interMod == "MUL":
if mulBias is None:
mulBias = config.mulBias
output = (x + mulBias) * (y + mulBias)
elif interMod == "DIAG":
W = getWeight((dim, )) # change initialization?
b = getBias((dim, ))
activations = x * W * y + b
elif interMod == "BL":
W = getWeight((dim, dim))
b = getBias((dim, ))
output = multiply(x, W) * y + b
else: # "ADD"
output = tf.tanh(x + y)
# concatenation
if concat is not None:
concatVals = projVals if concat.get("proj", False) else origVals
if concat.get("x", False):
output = tf.concat([output, concatVals["x"]], axis = -1)
dim += concatVals["dim"]
if concat.get("y", False):
output = ops.concat(output, concatVals["y"], extendY = extendY)
dim += concatVals["dim"]
return output, dim
######################################## rnns ########################################
'''
Creates an RNN cell.
Args:
hdim: the hidden dimension of the RNN cell.
reuse: whether the cell should reuse parameters or create new ones.
cellType: the cell type
RNN, GRU, LSTM, MiGRU, MiLSTM, ProjLSTM
act: the cell activation
NON, TANH, SIGMOID, RELU, ELU
projDim: if ProjLSTM, the dimension for the states projection
Returns the cell.
'''
# tf.nn.rnn_cell.MultiRNNCell([cell(hDim, reuse = reuse) for _ in config.encNumLayers])
# note that config.enc params not general
def createCell(hDim, reuse, cellType = None, act = None, projDim = None):
if cellType is None:
cellType = config.encType
activation = activations.get(act, None)
if cellType == "ProjLSTM":
cell = tf.nn.rnn_cell.LSTMCell
if projDim is None:
projDim = config.cellDim
cell = cell(hDim, num_proj = projDim, reuse = reuse, activation = activation)
return cell
cells = {
"RNN": tf.nn.rnn_cell.BasicRNNCell,
"GRU": tf.nn.rnn_cell.GRUCell,
"LSTM": tf.nn.rnn_cell.BasicLSTMCell,
"MiGRU": MiGRUCell,
"MiLSTM": MiLSTMCell
}
cell = cells[cellType](hDim, reuse = reuse, activation = activation)
return cell
'''
Runs an forward RNN layer.
Args:
inSeq: the input sequence to run the RNN over.
[batchSize, sequenceLength, inDim]
seqL: the sequence matching lengths.
[batchSize, 1]
hDim: hidden dimension of the RNN.
cellType: the cell type
RNN, GRU, LSTM, MiGRU, MiLSTM, ProjLSTM
dropout: value for dropout over input sequence
varDp: if not None, state and input variational dropouts to apply.
dimension of input has to be supported (inputSize).
Returns the outputs sequence and final RNN state.
'''
# varDp = {"stateDp": float, "inputDp": float, "inputSize": int}
# proj = {"output": bool, "state": bool, "dim": int, "dropout": float, "act": str}
def fwRNNLayer(inSeq, seqL, hDim, cellType = None, dropout = 1.0, varDp = None,
name = "", reuse = None): # proj = None
with tf.variable_scope("rnnLayer" + name, reuse = reuse):
batchSize = tf.shape(inSeq)[0]
cell = createCell(hDim, reuse, cellType) # passing reuse isn't mandatory
if varDp is not None:
cell = tf.contrib.rnn.DropoutWrapper(cell,
state_keep_prob = varDp["stateDp"],
input_keep_prob = varDp["inputDp"],
variational_recurrent = True, input_size = varDp["inputSize"], dtype = tf.float32)
else:
inSeq = tf.nn.dropout(inSeq, dropout)
initialState = cell.zero_state(batchSize, tf.float32)
outSeq, lastState = tf.nn.dynamic_rnn(cell, inSeq,
sequence_length = seqL,
initial_state = initialState,
swap_memory = True)
if isinstance(lastState, tf.nn.rnn_cell.LSTMStateTuple):
lastState = lastState.h
# if proj is not None:
# if proj["output"]:
# outSeq = linear(outSeq, cell.output_size, proj["dim"], act = proj["act"],
# dropout = proj["dropout"], name = "projOutput")
# if proj["state"]:
# lastState = linear(lastState, cell.state_size, proj["dim"], act = proj["act"],
# dropout = proj["dropout"], name = "projState")
return outSeq, lastState
'''
Runs an bidirectional RNN layer.
Args:
inSeq: the input sequence to run the RNN over.
[batchSize, sequenceLength, inDim]
seqL: the sequence matching lengths.
[batchSize, 1]
hDim: hidden dimension of the RNN.
cellType: the cell type
RNN, GRU, LSTM, MiGRU, MiLSTM
dropout: value for dropout over input sequence
varDp: if not None, state and input variational dropouts to apply.
dimension of input has to be supported (inputSize).
Returns the outputs sequence and final RNN state.
'''
# varDp = {"stateDp": float, "inputDp": float, "inputSize": int}
# proj = {"output": bool, "state": bool, "dim": int, "dropout": float, "act": str}
def biRNNLayer(inSeq, seqL, hDim, cellType = None, dropout = 1.0, varDp = None,
name = "", reuse = None): # proj = None,
with tf.variable_scope("birnnLayer" + name, reuse = reuse):
batchSize = tf.shape(inSeq)[0]
with tf.variable_scope("fw"):
cellFw = createCell(hDim, reuse, cellType)
with tf.variable_scope("bw"):
cellBw = createCell(hDim, reuse, cellType)
if varDp is not None:
cellFw = tf.contrib.rnn.DropoutWrapper(cellFw,
state_keep_prob = varDp["stateDp"],
input_keep_prob = varDp["inputDp"],
variational_recurrent = True, input_size = varDp["inputSize"], dtype = tf.float32)
cellBw = tf.contrib.rnn.DropoutWrapper(cellBw,
state_keep_prob = varDp["stateDp"],
input_keep_prob = varDp["inputDp"],
variational_recurrent = True, input_size = varDp["inputSize"], dtype = tf.float32)
else:
inSeq = tf.nn.dropout(inSeq, dropout)
initialStateFw = cellFw.zero_state(batchSize, tf.float32)
initialStateBw = cellBw.zero_state(batchSize, tf.float32)
(outSeqFw, outSeqBw), (lastStateFw, lastStateBw) = tf.nn.bidirectional_dynamic_rnn(
cellFw, cellBw, inSeq,
sequence_length = seqL,
initial_state_fw = initialStateFw,
initial_state_bw = initialStateBw,
swap_memory = True)
if isinstance(lastStateFw, tf.nn.rnn_cell.LSTMStateTuple):
lastStateFw = lastStateFw.h # take c?
lastStateBw = lastStateBw.h
outSeq = tf.concat([outSeqFw, outSeqBw], axis = -1)
lastState = tf.concat([lastStateFw, lastStateBw], axis = -1)
# if proj is not None:
# if proj["output"]:
# outSeq = linear(outSeq, cellFw.output_size + cellFw.output_size,
# proj["dim"], act = proj["act"], dropout = proj["dropout"],
# name = "projOutput")
# if proj["state"]:
# lastState = linear(lastState, cellFw.state_size + cellFw.state_size,
# proj["dim"], act = proj["act"], dropout = proj["dropout"],
# name = "projState")
return outSeq, lastState
# int(hDim / 2) for biRNN?
'''
Runs an RNN layer by calling biRNN or fwRNN.
Args:
inSeq: the input sequence to run the RNN over.
[batchSize, sequenceLength, inDim]
seqL: the sequence matching lengths.
[batchSize, 1]
hDim: hidden dimension of the RNN.
bi: true to run bidirectional rnn.
cellType: the cell type
RNN, GRU, LSTM, MiGRU, MiLSTM
dropout: value for dropout over input sequence
varDp: if not None, state and input variational dropouts to apply.
dimension of input has to be supported (inputSize).
Returns the outputs sequence and final RNN state.
'''
# proj = {"output": bool, "state": bool, "dim": int, "dropout": float, "act": str}
# varDp = {"stateDp": float, "inputDp": float, "inputSize": int}
def RNNLayer(inSeq, seqL, hDim, bi = None, cellType = None, dropout = 1.0, varDp = None,
name = "", reuse = None): # proj = None
with tf.variable_scope("rnnLayer" + name, reuse = reuse):
if bi is None:
bi = config.encBi
rnn = biRNNLayer if bi else fwRNNLayer
if bi:
hDim = int(hDim / 2)
return rnn(inSeq, seqL, hDim, cellType = cellType, dropout = dropout, varDp = varDp) # , proj = proj
# tf counterpart?
# hDim = config.moduleDim
def multigridRNNLayer(featrues, h, w, dim, name = "", reuse = None):
with tf.variable_scope("multigridRNNLayer" + name, reuse = reuse):
featrues = linear(featrues, dim, dim / 2, name = "i")
output0 = gridRNNLayer(featrues, h, w, dim, right = True, down = True, name = "rd")
output1 = gridRNNLayer(featrues, h, w, dim, right = True, down = False, name = "r")
output2 = gridRNNLayer(featrues, h, w, dim, right = False, down = True, name = "d")
output3 = gridRNNLayer(featrues, h, w, dim, right = False, down = False, name = "NON")
output = tf.concat([output0, output1, output2, output3], axis = -1)
output = linear(output, 2 * dim, dim, name = "o")
return outputs
# h,w should be constants
def gridRNNLayer(features, h, w, dim, right, down, name = "", reuse = None):
with tf.variable_scope("gridRNNLayer" + name):
batchSize = tf.shape(features)[0]
cell = createCell(dim, reuse = reuse, cellType = config.stemGridRnnMod,
act = config.stemGridAct)
initialState = cell.zero_state(batchSize, tf.float32)
inputs = [tf.unstack(row, w, axis = 1) for row in tf.unstack(features, h, axis = 1)]
states = [[None for _ in range(w)] for _ in range(h)]
iAxis = range(h) if down else (range(h)[::-1])
jAxis = range(w) if right else (range(w)[::-1])
iPrev = -1 if down else 1
jPrev = -1 if right else 1
prevState = lambda i,j: states[i][j] if (i >= 0 and i < h and j >= 0 and j < w) else initialState
for i in iAxis:
for j in jAxis:
prevs = tf.concat((prevState(i + iPrev, j), prevState(i, j + jPrev)), axis = -1)
curr = inputs[i][j]
_, states[i][j] = cell(prevs, curr)
outputs = [tf.stack(row, axis = 1) for row in states]
outputs = tf.stack(outputs, axis = 1)
return outputs
# tf seq2seq?
# def projRNNLayer(inSeq, seqL, hDim, labels, labelsNum, labelsDim, labelsEmb, name = "", reuse = None):
# with tf.variable_scope("projRNNLayer" + name):
# batchSize = tf.shape(features)[0]
# cell = createCell(hDim, reuse = reuse)
# projCell = ProjWrapper(cell, labelsNum, labelsDim, labelsEmb, # config.wrdEmbDim
# feedPrev = True, dropout = 1.0, config,
# temperature = 1.0, clevr_sample = False, reuse)
# initialState = projCell.zero_state(batchSize, tf.float32)
# if config.soft:
# inSeq = inSeq
# # outputs, _ = tf.nn.static_rnn(projCell, inputs,
# # sequence_length = seqL,
# # initial_state = initialState)
# inSeq = tf.unstack(inSeq, axis = 1)
# state = initialState
# logitsList = []
# chosenList = []
# for inp in inSeq:
# (logits, chosen), state = projCell(inp, state)
# logitsList.append(logits)
# chosenList.append(chosen)
# projCell.reuse = True
# logitsOut = tf.stack(logitsList, axis = 1)
# chosenOut = tf.stack(chosenList, axis = 1)
# outputs = (logitsOut, chosenOut)
# else:
# labels = tf.to_float(labels)
# labels = tf.concat([tf.zeros((batchSize, 1)), labels], axis = 1)[:, :-1] # ,newaxis
# inSeq = tf.concat([inSeq, tf.expand_dims(labels, axis = -1)], axis = -1)
# outputs, _ = tf.nn.dynamic_rnn(projCell, inSeq,
# sequence_length = seqL,
# initial_state = initialState,
# swap_memory = True)
# return outputs #, labelsEmb
############################### variational dropout ###############################
'''
Generates a variational dropout mask for a given shape and a dropout
probability value.
'''
def generateVarDpMask(shape, keepProb):
randomTensor = tf.to_float(keepProb)
randomTensor += tf.random_uniform(shape, minval = 0, maxval = 1)
binaryTensor = tf.floor(randomTensor)
mask = tf.to_float(binaryTensor)
return mask
'''
Applies the a variational dropout over an input, given dropout mask
and a dropout probability value.
'''
def applyVarDpMask(inp, mask, keepProb):
ret = (tf.div(inp, tf.to_float(keepProb))) * mask
return ret