Draft towards 2nd orthogonalization

This commit is contained in:
Daniel Povey 2022-05-16 16:16:12 +08:00
parent 8aeaf1421a
commit 67f916e599
2 changed files with 405 additions and 1 deletions

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#!/usr/bin/env python3
# Copyright (c) 2022 Xiaomi Corporation (author: Daniel Povey)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import copy
import math
import warnings
from typing import Optional, Tuple
import logging
import torch
from torch import Tensor, nn
# some utilities for diagnalizing models (rotating their parameters matrices
# so that large and small parameter values are separated as much as possible).
def _get_normalized_covar(x: Tensor) -> Tensor:
"""
Returns a covariance matrix normalized to have trace==dim, equal to
matmul(x , x.t()) times a constant.
Args:
x: a matrix of shape (i, j)
Returns: a covariance matrix of shape (i, i), equal to matmul(x, x.t())
"""
covar = torch.matmul(x, x.t())
return covar * (x.shape[0] / (covar.trace() + 1.0e-20))
@torch.no_grad()
def get_diag_covar_in(m: nn.Module) -> Tensor:
"""
Returns a covariance matrix that shows, in the input space of
this module, which direction parameter matrices vary in.
"""
if isinstance(m, nn.Linear):
return _get_normalized_covar(m.weight.t());
elif isinstance(m, nn.Conv1d) or isinstance(m, nn.Conv2d):
# m.weight is of size (out_channels, in_channels, kernel_size)
# or (out_channels, in_channels, kernel_dim0, kernel_dim1)
# assert here that groups == 1
w = m.weight
assert m.groups == 1
out_channels = w.shape[0]
in_channels = w.shape[1]
w = w.reshape(out_channels, in_channels, -1)
w = w.permute(1, 0, 2) # (in_channels, out_channels, kernel_size)
w = w.reshape(in_channels, -1)
return _get_normalized_covar(w) # (in_channels, in_channels)
elif isinstance(m, nn.Sequential):
return get_diag_covar_in(m[0])
else:
# some modules have this function; if not, at this point, it is an error.
return m.get_diag_covar_in()
@torch.no_grad()
def get_diag_covar_out(m: nn.Module) -> Tensor:
"""
Returns a covariance matrix that shows, in the output space of
this module, which direction parameter matrices vary in.
"""
if isinstance(m, nn.Linear):
return _get_normalized_covar(m.weight);
elif isinstance(m, nn.Conv1d) or isinstance(m, nn.Conv2d):
# m.weight is of size (out_channels, in_channels, kernel_size)
# or (out_channels, in_channels, kernel_dim0, kernel_dim1)
# assert here that groups == 1
w = m.weight
assert m.groups == 1
out_channels = w.shape[0]
in_channels = w.shape[1]
w = w.reshape(out_channels, -1)
return _get_normalized_covar(w) # (out_channels, out_channels)
w = w.permute(1, 0, 2) # (in_channels, out_channels, kernel_size)
w = w.reshape(in_channels, -1)
return _get_normalized_covar(x) # (in_channels, in_channels)
elif isinstance(m, nn.Sequential):
return get_diag_covar_out(m[-1])
else:
# some modules have this function; if not, at this point, it is an error.
return m.get_diag_covar_out()
@torch.no_grad()
def get_diag_covar_inout(m: nn.Module) -> Tensor:
"""
Returns a covariance matrix that shows, in the input and
output space of this module, which are assumed to be the
same (e.g if it is a module intended to be added to a residual/
bypass connection),
which direction parameter matrices vary in.
"""
if isinstance(m, nn.Sequential):
# this is only correct if it's a Sequential of non-residual modules.
return get_diag_covar_in(m[0]) + get_diag_covar_out(m[-1])
else:
# some modules have this function; if not, at this point, it is an error.
return m.get_diag_covar_inout()
@torch.no_grad()
def apply_transformation_in(m: nn.Module, t: Tensor) -> None:
"""
Applies this transformation matrix on the input space of this module.
Args:
m: module to transform on the input space
t: transformation matrix, indexed (new_dim_in, old_dim_in)
"""
if isinstance(m, nn.Linear):
m.weight[:] = torch.matmul(m.weight, t.t())
elif isinstance(m, nn.Conv1d) or isinstance(m, nn.Conv2d):
# m.weight is of size (out_channels, in_channels, kernel_size)
# or (out_channels, in_channels, kernel_dim0, kernel_dim1)
# assert here that groups == 1
w = m.weight
assert m.groups == 1
out_channels = w.shape[0]
in_channels = w.shape[1]
w = w.reshape(out_channels, in_channels, -1)
w = w.permute(1, 0, 2) # (in_channels, out_channels, kernel_size)
w = w.reshape(in_channels, -1)
w = torch.matmul(t, w).reshape(in_channels, out_channels, -1) # (in_channels, out_channels, kernel_size)
w = w.permute(1, 0, 2) # (out_channels, in_channels, kernel_size)
w = w.reshape(m.weight.shape) # (out_channels, in_channels, [1 or 2 kernel dims])
m.weight[:] = w
elif isinstance(m, nn.Sequential):
apply_transformation_in(m[0])
else:
# some modules have this function; if not, at this point, it is an error.
m.apply_transformation_in(t)
@torch.no_grad()
def apply_transformation_out(m: nn.Module, t: Tensor) -> None:
"""
Applies this transformation matrix on the output space of this module.
Args:
m: module to transform on the input space
t: transformation matrix, indexed (new_dim_out, old_dim_out)
"""
if isinstance(m, nn.Linear):
m.weight[:] = torch.matmul(t, m.weight)
if m.bias is not None:
m.bias[:] = torch.matmul(t, m.bias)
elif isinstance(m, nn.Conv1d) or isinstance(m, nn.Conv2d):
# m.weight is of size (out_channels, in_channels, kernel_size)
# or (out_channels, in_channels, kernel_dim0, kernel_dim1)
# assert here that groups == 1
w = m.weight
assert m.groups == 1
out_channels = w.shape[0]
in_channels = w.shape[1]
w = w.reshape(out_channels, -1)
w = torch.matmul(t, w)
w = w.reshape(m.weight.shape) # (out_channels, in_channels, [1 or 2 kernel dims])
m.weight[:] = w
if m.bias is not None:
m.bias[:] = torch.matmul(t, m.bias)
elif isinstance(m, nn.Sequential):
apply_transformation_out(m[-1])
else:
# some modules have this function; if not, at this point, it is an error.
m.apply_transformation_out(t)
@torch.no_grad()
def apply_transformation_inout(m: nn.Module, t: Tensor) -> None:
if isinstance(m, nn.Sequential):
apply_transformation_in(m, t)
apply_transformation_out(m, t)
else:
# some modules have this function; if not, at this point, it is an error.
m.apply_transformation_inout(t)
def get_transformation(cov: Tensor) -> Tensor:
"""
Returns a covariance-diagonalizing transformation that diagonalizes
the covariance matrix that is passed in.
Args: cov, of shape (dim0, dim0).
Returns: a transformation indexed (new_dim0, old_dim0), i.e. of
shape dim0 by dim0 but 1st index is the newly created indexes.
"""
cov = get_normalized_covar(args[0])
for a in args[1:]:
cov += get_normalized_covar(a)
old_diag_stddev = cov.diag().var().sqrt().item()
l, U = cov.symeig(eigenvectors=True)
new_diag_stddev = l.var().sqrt().item()
logging.info(f"Variance of diag of param-var changed from {old_diag_stddev:.3e} "
f"to {new_diag_stddev:.3e}")
return U.t() # U.t() is indexed (new_dim, old_dim)

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../pruned_transducer_stateless2/model.py

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# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang, Wei Kang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import k2
import torch
from torch import Tensor
import torch.nn as nn
from encoder_interface import EncoderInterface
from scaling import ScaledLinear
from diagonalize import get_diag_covar_in
from icefall.utils import add_sos
class Transducer(nn.Module):
"""It implements https://arxiv.org/pdf/1211.3711.pdf
"Sequence Transduction with Recurrent Neural Networks"
"""
def __init__(
self,
encoder: EncoderInterface,
decoder: nn.Module,
joiner: nn.Module,
encoder_dim: int,
decoder_dim: int,
joiner_dim: int,
vocab_size: int,
):
"""
Args:
encoder:
It is the transcription network in the paper. Its accepts
two inputs: `x` of (N, T, encoder_dim) and `x_lens` of shape (N,).
It returns two tensors: `logits` of shape (N, T, encoder_dm) and
`logit_lens` of shape (N,).
decoder:
It is the prediction network in the paper. Its input shape
is (N, U) and its output shape is (N, U, decoder_dim).
It should contain one attribute: `blank_id`.
joiner:
It has two inputs with shapes: (N, T, encoder_dim) and (N, U, decoder_dim).
Its output shape is (N, T, U, vocab_size). Note that its output contains
unnormalized probs, i.e., not processed by log-softmax.
"""
super().__init__()
assert isinstance(encoder, EncoderInterface), type(encoder)
assert hasattr(decoder, "blank_id")
self.encoder = encoder
self.decoder = decoder
self.joiner = joiner
self.simple_am_proj = ScaledLinear(
encoder_dim, vocab_size, initial_speed=0.5
)
self.simple_lm_proj = ScaledLinear(decoder_dim, vocab_size)
def forward(
self,
x: torch.Tensor,
x_lens: torch.Tensor,
y: k2.RaggedTensor,
prune_range: int = 5,
am_scale: float = 0.0,
lm_scale: float = 0.0,
warmup: float = 1.0,
) -> torch.Tensor:
"""
Args:
x:
A 3-D tensor of shape (N, T, C).
x_lens:
A 1-D tensor of shape (N,). It contains the number of frames in `x`
before padding.
y:
A ragged tensor with 2 axes [utt][label]. It contains labels of each
utterance.
prune_range:
The prune range for rnnt loss, it means how many symbols(context)
we are considering for each frame to compute the loss.
am_scale:
The scale to smooth the loss with am (output of encoder network)
part
lm_scale:
The scale to smooth the loss with lm (output of predictor network)
part
warmup:
A value warmup >= 0 that determines which modules are active, values
warmup > 1 "are fully warmed up" and all modules will be active.
Returns:
Return the transducer loss.
Note:
Regarding am_scale & lm_scale, it will make the loss-function one of
the form:
lm_scale * lm_probs + am_scale * am_probs +
(1-lm_scale-am_scale) * combined_probs
"""
assert x.ndim == 3, x.shape
assert x_lens.ndim == 1, x_lens.shape
assert y.num_axes == 2, y.num_axes
assert x.size(0) == x_lens.size(0) == y.dim0
encoder_out, x_lens = self.encoder(x, x_lens, warmup=warmup)
assert torch.all(x_lens > 0)
# Now for the decoder, i.e., the prediction network
row_splits = y.shape.row_splits(1)
y_lens = row_splits[1:] - row_splits[:-1]
blank_id = self.decoder.blank_id
sos_y = add_sos(y, sos_id=blank_id)
# sos_y_padded: [B, S + 1], start with SOS.
sos_y_padded = sos_y.pad(mode="constant", padding_value=blank_id)
# decoder_out: [B, S + 1, decoder_dim]
decoder_out = self.decoder(sos_y_padded)
# Note: y does not start with SOS
# y_padded : [B, S]
y_padded = y.pad(mode="constant", padding_value=0)
y_padded = y_padded.to(torch.int64)
boundary = torch.zeros(
(x.size(0), 4), dtype=torch.int64, device=x.device
)
boundary[:, 2] = y_lens
boundary[:, 3] = x_lens
lm = self.simple_lm_proj(decoder_out)
am = self.simple_am_proj(encoder_out)
with torch.cuda.amp.autocast(enabled=False):
simple_loss, (px_grad, py_grad) = k2.rnnt_loss_smoothed(
lm=lm.float(),
am=am.float(),
symbols=y_padded,
termination_symbol=blank_id,
lm_only_scale=lm_scale,
am_only_scale=am_scale,
boundary=boundary,
reduction="sum",
return_grad=True,
)
# ranges : [B, T, prune_range]
ranges = k2.get_rnnt_prune_ranges(
px_grad=px_grad,
py_grad=py_grad,
boundary=boundary,
s_range=prune_range,
)
# am_pruned : [B, T, prune_range, encoder_dim]
# lm_pruned : [B, T, prune_range, decoder_dim]
am_pruned, lm_pruned = k2.do_rnnt_pruning(
am=self.joiner.encoder_proj(encoder_out),
lm=self.joiner.decoder_proj(decoder_out),
ranges=ranges,
)
# logits : [B, T, prune_range, vocab_size]
# project_input=False since we applied the decoder's input projections
# prior to do_rnnt_pruning (this is an optimization for speed).
logits = self.joiner(am_pruned, lm_pruned, project_input=False)
with torch.cuda.amp.autocast(enabled=False):
pruned_loss = k2.rnnt_loss_pruned(
logits=logits.float(),
symbols=y_padded,
ranges=ranges,
termination_symbol=blank_id,
boundary=boundary,
reduction="sum",
)
return (simple_loss, pruned_loss)
def get_diag_covar_in(self) -> Tensor:
return (get_diag_covar_in(self.simple_am_proj) +
get_diag_covar_in(joiner.encoder_proj) +
self.encoder.get_diag_covar_out())