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laydi/scripts/lpls/lpls.py

414 lines
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Python

import sys
from pylab import *
import matplotlib
from scipy import *
from scipy.linalg import inv,norm
sys.path.append("/home/flatberg/fluents/fluents/lib")
import select_generators
sys.path.remove("/home/flatberg/fluents/fluents/lib")
def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], scale='scores', verbose=True):
""" L-shaped Partial Least Sqaures Regression by the nipals algorithm.
(X!Z)->Y
:input:
X : data matrix (m, n)
Y : data matrix (m, l)
Z : data matrix (n, o)
:output:
T : X-scores
W : X-weights/Z-weights
P : X-loadings
Q : Y-loadings
U : X-Y relation
L : Z-scores
K : Z-loads
B : Regression coefficients X->Y
b0: Regression coefficient intercept
evx : X-explained variance
evy : Y-explained variance
evz : Z-explained variance
:Notes:
"""
if mean_ctr:
xctr, yctr, zctr = mean_ctr
X, mnX = center(X, xctr)
Y, mnY = center(Y, xctr)
Z, mnZ = center(Z, zctr)
varX = pow(X, 2).sum()
varY = pow(Y, 2).sum()
varZ = pow(Z, 2).sum()
m, n = X.shape
k, l = Y.shape
u, o = Z.shape
# initialize
U = empty((k, a_max))
Q = empty((l, a_max))
T = empty((m, a_max))
W = empty((n, a_max))
P = empty((n, a_max))
K = empty((o, a_max))
L = empty((u, a_max))
B = empty((a_max, n, l))
b0 = empty((a_max, m, l))
var_x = empty((a_max,))
var_y = empty((a_max,))
var_z = empty((a_max,))
for a in range(a_max):
if verbose:
print "\n Working on comp. %s" %a
u = Y[:,:1]
diff = 1
MAX_ITER = 100
lim = 1e-7
niter = 0
while (diff>lim and niter<MAX_ITER):
niter += 1
u1 = u.copy()
w = dot(X.T, u)
w = w/sqrt(dot(w.T, w))
l = dot(Z, w)
k = dot(Z.T, l)
k = k/sqrt(dot(k.T, k))
w = alpha*k + (1-alpha)*w
w = w/sqrt(dot(w.T, w))
t = dot(X, w)
c = dot(Y.T, t)
c = c/sqrt(dot(c.T, c))
u = dot(Y, c)
diff = abs(u1 - u).max()
if verbose:
print "Converged after %s iterations" %niter
tt = dot(t.T, t)
p = dot(X.T, t)/tt
q = dot(Y.T, t)/tt
l = dot(Z, w)
U[:,a] = u.ravel()
W[:,a] = w.ravel()
P[:,a] = p.ravel()
T[:,a] = t.ravel()
Q[:,a] = q.ravel()
L[:,a] = l.ravel()
K[:,a] = k.ravel()
X = X - dot(t, p.T)
Y = Y - dot(t, q.T)
Z = (Z.T - dot(w, l.T)).T
var_x[a] = pow(X, 2).sum()
var_y[a] = pow(Y, 2).sum()
var_z[a] = pow(Z, 2).sum()
B[a] = dot(dot(W[:,:a+1], inv(dot(P[:,:a+1].T, W[:,:a+1]))), Q[:,:a+1].T)
b0[a] = mnY - dot(mnX, B[a])
# variance explained
evx = 100.0*(1 - var_x/varX)
evy = 100.0*(1 - var_y/varY)
evz = 100.0*(1 - var_z/varZ)
if scale=='loads':
tnorm = apply_along_axis(norm, 0, T)
T = T/tnorm
Q = Q*tnorm
W = W*tnorm
return T, W, P, Q, U, L, K, B, b0, evx, evy, evz
def svd_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], verbose=True):
"""
NB: In the works ...
L-shaped Partial Least Sqaures Regression by the svd algorithm.
(X!Z)->Y
:input:
X : data matrix (m, n)
Y : data matrix (m, l)
Z : data matrix (n, o)
:output:
T : X-scores
W : X-weights/Z-weights
P : X-loadings
Q : Y-loadings
U : X-Y relation
L : Z-scores
K : Z-loads
B : Regression coefficients X->Y
b0: Regression coefficient intercept
evx : X-explained variance
evy : Y-explained variance
evz : Z-explained variance
:Notes:
Not quite there ,,,,,,,,,,,,,,
"""
if mean_ctr:
xctr, yctr, zctr = mean_ctr
X, mnX = center(X, xctr)
Y, mnY = center(Y, xctr)
Z, mnZ = center(Z, zctr)
varX = pow(X, 2).sum()
varY = pow(Y, 2).sum()
varZ = pow(Z, 2).sum()
m, n = X.shape
k, l = Y.shape
u, o = Z.shape
# initialize
U = empty((k, a_max))
Q = empty((l, a_max))
T = empty((m, a_max))
W = empty((n, a_max))
P = empty((n, a_max))
K = empty((o, a_max))
L = empty((u, a_max))
var_x = empty((a_max,))
var_y = empty((a_max,))
var_z = empty((a_max,))
for a in range(a_max):
if verbose:
print "\n Working on comp. %s" %a
xyz = dot(dot(Z,X.T),Y)
u,s,vt = linalg.svd(xyz, 0)
w = u[:,o]
t = dot(X, w)
tt = dot(t.T, t)
p = dot(X.T, t)/tt
q = dot(Y.T, t)/tt
l = dot(Z.T, w)
W[:,a] = w.ravel()
P[:,a] = p.ravel()
T[:,a] = t.ravel()
Q[:,a] = q.ravel()
L[:,a] = l.ravel()
K[:,a] = k.ravel()
X = X - dot(t, p.T)
Y = Y - dot(t, q.T)
Z = (Z.T - dot(w, l.T)).T
var_x[a] = pow(X, 2).sum()
var_y[a] = pow(Y, 2).sum()
var_z[a] = pow(Z, 2).sum()
B = dot(dot(W, inv(dot(P.T, W))), Q.T)
b0 = mnY - dot(mnX, B)
# variance explained
evx = 100.0*(1 - var_x/varX)
evy = 100.0*(1 - var_y/varY)
evz = 100.0*(1 - var_z/varZ)
return T, W, P, Q, U, L, K, B, b0, evx, evy, evz
def lplsr(X, Y, Z, a_max, mean_ctr=[2,0,1]):
""" Haralds LPLS.
"""
if mean_ctr!=None:
xctr, yctr, zctr = mean_ctr
X, mnX = center(X, xctr)
Y, mnY = center(Y, yctr)
Z, mnZ = center(Z, zctr)
varX = pow(X, 2).sum()
varY = pow(Y, 2).sum()
varZ = pow(Z, 2).sum()
m, n = X.shape
k, l = Y.shape
u, o = Z.shape
# initialize
Wy = empty((l, a_max))
Py = empty((l, a_max))
Ty = empty((m, a_max))
Tz = empty((o, a_max))
Wz = empty((u, a_max))
Pz = empty((u, a_max))
var_x = empty((a_max,))
var_y = empty((a_max,))
var_z = empty((a_max,))
# residuals
Ey = Y.copy()
Ez = Z.copy()
Ex = X.copy()
for i in range(a_max):
YtXZ = dot(Ey.T, dot(X, Ez.T))
U, S, V = linalg.svd(YtXZ)
wy = U[:,0]
print wy
wz = V[0,:]
ty = dot(Ey, wy)
tz = dot(Ez.T, wz)
py = dot(Ey.T, ty)/dot(ty.T,ty)
pz = dot(Ez, tz)/dot(tz.T,tz)
Wy[:,i] = wy
Wz[:,i] = wz
Ty[:,i] = ty
Tz[:,i] = tz
Py[:,i] = py
Pz[:,i] = pz
Ey = Ey - outer(ty, py.T)
Ez = (Ez.T - outer(tz, pz.T)).T
var_y[i] = pow(Ey, 2).sum()
var_z[i] = pow(Ez, 2).sum()
tyd = apply_along_axis(norm, 0, Ty)
tzd = apply_along_axis(norm, 0, Tz)
Tyu = Ty/tyd
Tzu = Tz/tzd
C = dot(dot(Tyu.T, X), Tzu)
for i in range(a_max):
Ex = Ex - dot(dot(Ty[:,:i+1],C[:i+1,:i+1]), Tz[:,:i+1].T)
var_x[i] = pow(Ex,2).sum()
# variance explained
print "var_x:"
print var_x
print "varX total:"
print varX
evx = 100.0*(1 - var_x/varX)
evy = 100.0*(1 - var_y/varY)
evz = 100.0*(1 - var_z/varZ)
return Ty, Tz, Wy, Wz, Py, Pz, C, Ey, Ez, Ex, evx, evy, evz
def bifpls(X, Y, Z, a_max, alpha):
"""Swedssihsh LPLS by nipals.
"""
u = X[:,0]
Ey = Y.copy()
Ez = Z.copy()
for i in range(100):
w = dot(X.T,u)
w = w/vnorm(w)
t = dot(X, w)
q = dot(Ey, t.T)/dot(t.T,t)
qnorm = vnorm(q)
q = q/qnorm
v = dot(Ez, q)
s = dot(Ez.T, v)/dot(v.T,v)
v = v*vnorm(s)
s = s/vnorm(s)
c = qnorm*(alpha*q + (1-alpha)*s)
u = dot(Ey, c)/dot(s.T,s)
p = dot(X.T, t)/dot(t.T,t)
v2 = dot(Ez, s)/dot(s.T,s)
Ey = Ey - dot(t, p.T)
Ez = Ez - dot(v2, c.T)
# variance explained
evx = 100.0*(1 - var_x/varX)
evy = 100.0*(1 - var_y/varY)
evz = 100.0*(1 - var_z/varZ)
def center(a, axis):
# 0 = col center, 1 = row center, 2 = double center
# -1 = nothing
if axis==-1:
mn = zeros((a.shape[1],))
return a - mn, mn
elif axis==0:
mn = a.mean(0)
return a - mn, mn
elif axis==1:
mn = a.mean(1)[:,newaxis]
return a - mn , mn
elif axis==2:
mn = a.mean(0) + a.mean(1)[:,newaxis] - a.mean()
return a - mn, mn
else:
raise IOError("input error: axis must be in [-1,0,1,2]")
def correlation_loadings(D, T, P, test=True):
""" Returns correlation loadings.
:input:
- D: [nsamps, nvars], data (non-centered data)
- T: [nsamps, a_max], Scores
- P: [nvars, a_max], Loadings
:ouput:
- Rloads: [nvars, a_max], Correlation loadings
- rmseVars: [nvars], scaling coeff. for each var in D
:notes:
- FIXME: Calculation is not valid .... using corrceof instead
"""
nsamps, nvars = D.shape
nsampsT, a_max = T.shape
nvarsP, a_maxP = P.shape
if nsamps!=nsampsT: raise IOError("D/T mismatch")
if a_max!=a_maxP: raise IOError("a_max mismatch")
if nvars!=nvarsP: raise IOError("D/P mismatch")
#init
Rloads = empty((nvars, a_max), 'd')
stdvar = stats.std(D, 0)
rmseVars = sqrt(nsamps-1)*stdvar
# center
D = D - D.mean(0)
TT = diag(dot(T.T, T))
sTT = sqrt(TT)
for a in range(a_max):
Rloads[:,a] = sTT[a]*P[:,a]/rmseVars
R = empty_like(Rloads)
for a in range(a_max):
for k in range(nvars):
r = corrcoef(D[:,k], T[:,a])
R[k,a] = r[0,1]
#Rloads = R
return Rloads, R, rmseVars
def cv_lpls(X, Y, Z, a_max=2, nsets=None,alpha=.5):
"""Performs crossvalidation to get generalisation error in lpls"""
cv_iter = select_generators.pls_gen(X, Y, n_blocks=nsets,center=False,index_out=True)
k, l = Y.shape
Yhat = empty((a_max,k,l), 'd')
for i, (xcal,xi,ycal,yi,ind) in enumerate(cv_iter):
T, W, P, Q, U, L, K, B, b0, evx, evy, evz = nipals_lpls(xcal,ycal,Z,
a_max=a_max,
alpha=alpha,
mean_ctr=[2,0,1],
verbose=False)
for a in range(a_max):
Yhat[a,ind,:] = b0[a][0][0] + dot(xi, B[a])
Yhat_class = zeros_like(Yhat)
for a in range(a_max):
for i in range(k):
Yhat_class[a,i,argmax(Yhat[a,i,:])]=1.0
class_err = 100*((Yhat_class+Y)==2).sum(1)/Y.sum(0).astype('d')
sep = (Y - Yhat)**2
rmsep = sqrt(sep.mean(1))
return rmsep, Yhat, class_err
def jk_lpls(X, Y, Z, a_max, nsets=None, alpha=.5):
cv_iter = select_generators.pls_gen(X, Y, n_blocks=nsets,center=False,index_out=False)
m, n = X.shape
k, l = Y.shape
o, p = Z.shape
if nsets==None:
nsets = m
WWx = empty((nsets, n, a_max), 'd')
WWz = empty((nsets, o, a_max), 'd')
WWy = empty((nsets, l, a_max), 'd')
for i, (xcal,xi,ycal,yi) in enumerate(cv_iter):
T, W, P, Q, U, L, K, B, b0, evx, evy, evz = nipals_lpls(xcal,ycal,Z,
a_max=a_max,
alpha=alpha,
mean_ctr=[2,0,1],
scale='loads',
verbose=False)
WWx[i,:,:] = W
WWz[i,:,:] = L
WWy[i,:,:] = Q
return WWx, WWz, WWy