JittorMirror/python/jittor/linalg.py

433 lines
13 KiB
Python

# ***************************************************************
# Copyright (c) 2021 Jittor. All Rights Reserved.
# Maintainers:
# Haoyang Peng <2247838039@qq.com>
# Guowei Yang <471184555@qq.com>
# Dun Liang <randonlang@gmail.com>.
#
# This file is subject to the terms and conditions defined in
# file 'LICENSE.txt', which is part of this source code package.
# ***************************************************************
import jittor as jt
from functools import partial
#TODO:full_matrices=1
def svd(x):
r'''
calculate the Singular Value Decomposition of x.It follows the below fomula:
x = usv*
only support full matrices == False ver now, which means:
x's shape (...,M,K)
u's shape (...,M,K)
s's shape (...,K)
v's shape (...,K,N)
where K is min(M,N).
:param x:
:return:u,s,v.
'''
def forward_code(np, data):
a = data["inputs"][0]
u, s, v = data["outputs"]
#TODO:remove copyto
tu, ts, tv = np.linalg.svd(a, full_matrices=0)
np.copyto(u, tu)
np.copyto(s, ts)
np.copyto(v, tv)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
inp = data["inputs"][0]
out_index = data["out_index"]
u, s, v = data["f_outputs"]
v = T(v)
m, n = inp.shape[-2:]
k = np.min((m, n))
i = np.reshape(np.eye(k), np.concatenate((np.ones(inp.ndim - 2, dtype=int), (k, k))))
if out_index == 0:
f = 1 / (s[..., np.newaxis, :] ** 2 - s[..., :, np.newaxis] ** 2 + i)
gu = dout
utgu = _dot(T(u), gu)
t = (f * (utgu - T(utgu))) * s[..., np.newaxis, :]
t = _dot(_dot(u, t), T(v))
if m > n:
i_minus_uut = (np.reshape(np.eye(m), np.concatenate((np.ones(inp.ndim - 2, dtype=int), (m, m)))) -
_dot(u, np.conj(T(u))))
t = t + T(_dot(_dot(v / s[..., np.newaxis, :], T(gu)), i_minus_uut))
np.copyto(out, t)
elif out_index == 1:
gs = dout
t = i * gs[..., :, np.newaxis]
t = _dot(_dot(u, t), T(v))
np.copyto(out, t)
elif out_index == 2:
f = 1 / (s[..., np.newaxis, :] ** 2 - s[..., :, np.newaxis] ** 2 + i)
gv = dout
vtgv = _dot(T(v), gv)
t = s[..., :, np.newaxis] * (f * (vtgv - T(vtgv)))
t = _dot(_dot(u, t), T(v))
if m < n:
i_minus_vvt = (np.reshape(np.eye(n), np.concatenate((np.ones(inp.ndim - 2, dtype=int), (n, n)))) -
_dot(v, np.conj(T(v))))
t = t + T(_dot(_dot(u / s[..., np.newaxis, :], T(gv)), i_minus_vvt))
np.copyto(out, t)
m, n = x.shape[-2:]
k = min(m, n)
s1 = list(x.shape)
s1[-1] = k
s2 = list(x.shape)
s2[-2] = k
s3 = list(x.shape)[:-2]
s3.append(k)
u, s, v = jt.numpy_code(
[s1, s3, s2],
[x.dtype, x.dtype, x.dtype],
[x],
forward_code,
[backward_code],
)
return u, s, v
def eigh(x):
r"""
calculate the eigenvalues and eigenvectors of x.
:param x (...,M,M):
:return:w, v.
w (...,M) : the eigenvalues.
v (...,M,M) : normalized eigenvectors.
"""
def forward_code(np, data):
a = data["inputs"][0]
w, v = data["outputs"]
tw, tv = np.linalg.eigh(a, UPLO='L')
np.copyto(w, tw)
np.copyto(v, tv)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
inp = data["inputs"][0]
out_index = data["out_index"]
w, v = data["f_outputs"]
k = int(inp.shape[-1])
w_repeated = np.repeat(w[..., np.newaxis], k, axis=-1)
if out_index == 0:
t = _dot(v * dout[..., np.newaxis, :], T(v))
np.copyto(out, t)
elif out_index == 1:
if np.any(dout):
off_diag = np.ones((k, k)) - np.eye(k)
F = off_diag / (T(w_repeated) - w_repeated + np.eye(k))
t = _dot(_dot(v, F * _dot(T(v), dout)), T(v))
np.copyto(out, t)
sw = x.shape[:-2] + x.shape[-1:]
sv = x.shape
w, v = jt.numpy_code(
[sw, sv],
[x.dtype, x.dtype],
[x],
forward_code,
[backward_code],
)
return w, v
def inv(x):
r"""
calculate the inverse of x.
:param x (...,M,M):
:return:x^-1 (...,M,M).
"""
def forward_code(np, data):
a = data["inputs"][0]
m_a = data["outputs"][0]
t_a = np.linalg.inv(a)
np.copyto(m_a, t_a)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
lmx = data["f_outputs"]
mx = lmx[0]
t = -_dot(_dot(T(mx), dout), T(mx))
np.copyto(out, t)
lmx = jt.numpy_code(
[x.shape],
[x.dtype],
[x],
forward_code,
[backward_code],
)
mx = lmx[0]
return mx
def pinv(x):
r"""
calculate the pseudo-inverse of a x.
:param x (...,M,N)
:return: x's pinv (...N,M)
"""
def forward_code(np, data):
a = data["inputs"][0]
m_a = data["outputs"][0]
t_a = np.linalg.pinv(a)
np.copyto(m_a, t_a)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
inp = data["inputs"][0]
lmx = data["f_outputs"]
mx = lmx[0]
t = T(
-_dot(_dot(mx, T(dout)), mx)
+ _dot(_dot(_dot(mx, T(mx)), dout), np.eye(inp.shape[-2]) - _dot(inp, mx))
+ _dot(_dot(_dot(np.eye(mx.shape[-2]) - _dot(mx, inp), dout), T(mx)), mx)
)
np.copyto(out, t)
sw = list(x.shape[:-2]) + [x.shape[-1]] + [x.shape[-2]]
lmx = jt.numpy_code(
[sw],
[x.dtype],
[x],
forward_code,
[backward_code],
)
mx = lmx[0]
return mx
def det(x):
r"""
calculate the determinant of x.
:param x (...,M,M):
:return:|x| (...,1)
"""
def forward_code(np, data):
a = data["inputs"][0]
L = data["outputs"][0]
tL = np.linalg.det(a)
np.copyto(L, tL)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
f_out = data["f_outputs"][0]
inp = data["inputs"][0]
n_d = np.reshape(dout, np.shape(dout) + (1, 1))
n_o = np.reshape(f_out, np.shape(f_out) + (1, 1))
s = n_d * n_o * T(np.linalg.inv(inp))
np.copyto(out, s)
s = x.shape
x_s = s[:-2]
if len(s) == 2:
x_s.append(1)
l_det = jt.numpy_code(
[x_s],
[x.dtype],
[x],
forward_code,
[backward_code],
)
det = l_det[0]
return det
def slogdet(x):
r"""
calculate the sign and log of the determinant of x.
:param x (...,M,M):
:return sign, x's logdet.
sign array decides the sign of determinant and their values can be -1,0,1.Only Real number now.0 means det is 0 and logdet is -inf.
logdet in shape (...,1).
"""
def forward_code(np, data):
a = data["inputs"][0]
sign, m_a = data["outputs"]
sign_, t_a = np.linalg.slogdet(a)
np.copyto(m_a, t_a)
np.copyto(sign, sign_)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
inp = data["inputs"][0]
out_index = data["out_index"]
if out_index == 0:
np.copyto(out, 0)
if out_index == 1:
t = np.reshape(dout, np.shape(dout) + (1, 1))
t = t * T(np.linalg.inv(inp))
np.copyto(out, t)
s = x.shape
det_s = s[:-2]
if len(det_s) == 0:
det_s.append(1)
sign, mx = jt.numpy_code(
[det_s, det_s],
[x.dtype, x.dtype],
[x],
forward_code,
[backward_code],
)
return sign, mx
def cholesky(x):
r"""
do Cholesky decomposition of x in the form of below formula:
x = LL^T
x must be a Hermite and positive-definite matrix. L is a lower-triangular matrix.
:param x (...,M,M):
:return: L (...,M,M).
"""
def forward_code(np, data):
a = data["inputs"][0]
L = data["outputs"][0]
tL = np.linalg.cholesky(a)
np.copyto(L, tL)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
f_out = data["f_outputs"][0]
solve_trans = lambda a, b: np.linalg.solve(T(a), b)
phi = lambda X: np.tril(X) / (1. + np.eye(X.shape[-1]))
def conjugate_solve(L, X):
return solve_trans(L, T(solve_trans(L, T(X))))
s = conjugate_solve(f_out, phi(np.einsum('...ki,...kj->...ij', f_out, dout)))
s = (s + T(s)) / 2.
np.copyto(out, s)
lL = jt.numpy_code(
[x.shape],
[x.dtype],
[x],
forward_code,
[backward_code],
)
L = lL[0]
return L
def solve(a,b):
r"""
Solve a linear matrix equation Ax = B.This is done by calculating x = A^-1B.So A must not be singular.
:param a:(...,M,M)
:param b:(...,M)
:return:solution of Ax = b formula.x in the shape of (...M)
"""
def forward_code(np, data):
a, b = data["inputs"]
L = data["outputs"][0]
ans = np.linalg.solve(a, b)
np.copyto(L, ans)
def backward_code1(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
dout = data["dout"]
out = data["outputs"][0]
f_out = data["f_outputs"][0]
inp = data["inputs"][0]
updim = lambda x: x if x.ndim == a.ndim else x[..., None]
t = -_dot(updim(np.linalg.solve(T(inp), dout)), T(updim(f_out)))
np.copyto(out, t)
def backward_code2(np, data):
out = data["outputs"][0]
np.copyto(out, 0)
l_ans = jt.numpy_code(
[b.shape],
[b.dtype],
[a, b],
forward_code,
[backward_code1, backward_code2],
)
ans = l_ans[0]
return ans
def qr(x):
r"""
do the qr factorization of x in the below formula:
x = QR where Q is orthogonal matrix and R is upper-triangle matrix.
:param x (...,M,M):
:return:q,r as the result of qr factorization.They are both in the shape of (...,M,M).
"""
def forward_code(np, data):
a = data["inputs"][0]
q, r = data["outputs"]
Q, R = np.linalg.qr(a)
np.copyto(q,Q)
np.copyto(r,R)
def backward_code(np, data):
def T(x):
return np.swapaxes(x, -1, -2)
_dot = partial(np.einsum, '...ij,...jk->...ik')
_harmard = partial(np.einsum, '...ij,...ij->...ij')
dout = data["dout"]
out = data["outputs"][0]
q, r = data["f_outputs"]
out_index = data["out_index"]
#pl = np.tril(np.ones((inp.shape[-1],inp.shape[-1])))-diags
if out_index == 0: # Q_TERM
q_t = _dot(T(q),dout)
rhs_solve = q_t - T(q_t)
rhs_solve = T(np.tril(rhs_solve,-1))
qsolve = np.linalg.solve(r,rhs_solve)
qsolve = T(qsolve)
tq = _dot(q,qsolve)
np.copyto(out,tq)
else: #R_TERM
r_t = _dot(r ,T(dout))
rhs_solve = r_t - T(r_t)
rhs_solve = np.tril(rhs_solve,-1)
rhs_solve = T(rhs_solve)
r_solve = np.linalg.solve(r,rhs_solve)
tr = _dot(q,(T(r_solve) + dout))
np.copyto(out,tr)
q, r = jt.numpy_code(
[x.shape,x.shape],
[x.dtype,x.dtype],
[x],
forward_code,
[backward_code],
)
return q, r