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This commit is contained in:
Arnar Flatberg 2007-09-20 16:11:37 +00:00
parent 7e9a0882f1
commit 41f93c5989
4 changed files with 337 additions and 102 deletions

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@ -693,13 +693,13 @@ class LplsOptions(Options):
opt['mode'] = 'normal' # how much info to calculate
opt['amax'] = 10
opt['aopt'] = 3
opt['xz_alpha'] = 0.4
opt['xz_alpha'] = 0.6
opt['auto_aopt'] = False
opt['center'] = True
opt['center_mth'] = [2, 2, 1]
opt['center_mth'] = [2, 0, 2]
opt['scale'] = 'scores'
opt['calc_conf'] = True
opt['n_sets'] = 75
opt['calc_conf'] = False
opt['n_sets'] = 7
opt['strict'] = False
opt['p_center'] = 'med'
opt['alpha'] = .3

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@ -1,6 +1,6 @@
from scipy import zeros,zeros_like,sqrt,dot,trace,sign,round_,argmax,\
sort,ravel,newaxis,asarray,diag,sum,outer,argsort,arange,ones_like,\
all,apply_along_axis,eye
all,apply_along_axis,eye,atleast_2d
from scipy.linalg import svd,inv,norm,det,sqrtm
from scipy.stats import mean,median
from cx_utils import mat_center
@ -26,8 +26,8 @@ def hotelling(Pcv, P, p_center='med', cov_center='med',
m, n = P.shape
n_sets, n, amax = Pcv.shape
# allocate
T_sq = empty((n, ),dtype='f')
Cov_i = zeros((n, amax, amax),dtype='f')
T_sq = empty((n, ),dtype='d')
Cov_i = zeros((n, amax, amax),dtype='d')
# rotate sub_models to full model
if crot:
@ -56,10 +56,12 @@ def hotelling(Pcv, P, p_center='med', cov_center='med',
reg_cov = (1. - alpha)*Cov_i + alpha*Cov
for i in xrange(n):
Pc = P_ctr[i,:][:,newaxis]
#Pc = P_ctr[i,:][:,newaxis]
Pc = P_ctr[i,:]
sigma = reg_cov[i]
#T_sq[i] = sqrt(dot(dot(Pc.T, inv(sigma)), Pc).ravel())
T_sq[i] = dot(dot(Pc.T, inv(sigma)), Pc).ravel()
# T_sq[i] = (dot(Pc, inv(sigma) )*Pc).sum() #slow
T_sq[i] = dot(dot(Pc, inv(sigma)), Pc) # dont need to care about transposes
#T_sq[i] = dot(dot(Pc.T, inv(sigma)), Pc).ravel()
return T_sq
def procrustes(A, B, strict=True, center=False, verbose=False):
@ -147,10 +149,10 @@ def pls_qvals(a, b, aopt=None, alpha=.3,
tsq_full = hotelling(Wcv, dat['W'], p_center=p_center,
alpha=alpha, crot=crot, strict=strict,
cov_center=cov_center)
t0 = time.time()
#t0 = time.time()
Vs = shuffle_1d(bc, n_iter, axis=0)
for i, b_shuff in enumerate(Vs):
t1 = time.time()
#t1 = time.time()
if algo=='bridge':
dat = bridge(ac, b_shuff, aopt, 'loads','fast')
else:
@ -159,23 +161,10 @@ def pls_qvals(a, b, aopt=None, alpha=.3,
TSQ[:,i] = hotelling(Wcv, dat['W'], p_center=p_center,
alpha=alpha, crot=crot, strict=strict,
cov_center=cov_center)
print time.time() - t1
sort_index = argsort(tsq_full)[::-1]
back_sort_index = sort_index.argsort()
print time.time() - t0
# count false positives
tsq_full_sorted = tsq_full.take(sort_index)
for i in xrange(n_iter):
for j in xrange(n):
n_false[j,i] = sum(TSQ[:,i]>=tsq_full[j]) # number of false pos. genes (0-n)
false_pos = median(n_false, 1)
ll = arange(1, len(false_pos)+1, 1)
sort_qval = false_pos.take(sort_index)/ll
qval = false_pos/ll.take(back_sort_index)
print time.time() - t0
#return qval, false_pos, TSQ, tsq_full
return qval
#print time.time() - t1
return fdr(tsq_full, TSQ, median)
def ensure_strict(C, only_flips=True):
"""Ensure that a rotation matrix does only 90 degree rotations.
@ -267,6 +256,7 @@ def pls_qvals_II(a, b, aopt=None, center=True, alpha=.3,
qval = false_pos/ll.take(back_sort_index)
print time.time() - t0
#return qval, false_pos, TSQ, tsq_full
return qval
def leverage(aopt=1,*args):
@ -333,3 +323,107 @@ def vnorm(x):
This is considerably faster than linalg.norm
"""
return sqrt(dot(x,x.conj()))
def mahalanobis(a, loc=None, acov=None, invcov=None):
"""Returns the distance of each observation in a
from the location estimate (loc) of the data,
relative to the shape of the data.
a : data matrix (n observations in rows, p variables in columns)
loc : location estimate of the data (p-dimensional vector)
covmat or invcov : scatter estimate of the data or the inverse of the scatter estimate (pxp matrix)
:Returns:
A vector containing the distances of all the observations to locvct.
"""
n, p = a.shape
if loc==None:
loc = a.mean(0)
loc = atleast_2d(loc)
if loc.shape[1]==1:
loc = loc.T; #ensure rowvector
assert(loc.shape[1]==p)
xc = a - loc
if acov==None and invcov==None:
acov = dot(xc.T, xc)
if invcov != None:
covmat = atleast_2d(invcov)
if min(covmat.shape)==1:
covmat = diag(invcov.ravel())
else:
covmat = atleast_2d(acov)
if min(covmat.shape)==1:
covmat = diag(covmat.ravel())
covmat = inv(covmat)
# mdist = diag(dot(dot(xc, covmat),xc.T))
mdist = (dot(xc, covmat)*xc).sum(1)
return mdist
def lpls_qvals(a, b, c, aopt=None, alpha=.3, zx_alpha=.5, n_iter=20,center=True,
sim_method='shuffle',p_center='med', cov_center='med',crot=True, strict=False):
"""Returns qvals for l-pls model.
input:
a -- data matrix
b -- data matrix
c -- data matrix
aopt -- scalar, opt. number of components
alpha -- [0,1] regularisation parameter for T2-test
xz_alpha -- [0,1] how much z info to include
n_iter -- number of permutations
sim_method -- permutation method ['shuffle']
p_center -- location estimator for sub models ['med']
cov_center -- location estimator for covariance of submodels ['med']
crot -- bool, use rotations of sub models?
strict -- bool, use stict (rot/flips only) rotations?
"""
m, n = a.shape
TSQ = zeros((n, n_iter), dtype='d') # (nvars x n_subsets)
n_false = zeros((n, n_iter), dtype='d')
# Full model
dat = lpls(a, b, c, aopt, scale='loads')
Wcv = lpls_jk(a, b, c ,aopt, n_blocks=None, algo=algo,center=center)
tsq_x = hotelling(Wcv, dat['W'], p_center=p_center,alpha=alpha, crot=crot, strict=strict,
cov_center=cov_center)
Lcv = lpls_jk(a, b, c ,aopt, n_blocks=None, algo=algo,center=center)
tsq_z = hotelling(Lcv, dat['L'], p_center=p_center,alpha=alpha, crot=crot, strict=strict,
cov_center=cov_center)
# Perturbations
t0 = time.time()
Vs = shuffle_1d(b, n_iter, axis=0)
for i, b_shuff in enumerate(Vs):
t1 = time.time()
dat = pls(ac, b_shuff, aopt, 'loads', 'fast')
Wcv = pls_jkW(a, b_shuff, aopt, n_blocks=None, algo=algo)
TSQ[:,i] = hotelling(Wcv, dat['W'], p_center=p_center,
alpha=alpha, crot=crot, strict=strict,
cov_center=cov_center)
print time.time() - t1
return fdr(tsq_full, TSQ, median)
def fdr(tsq, tsqp, loc_method=median):
n, = tsq.shape
k, m = tsqp.shape
assert(n==k)
n_false = empty((n, m), 'd')
sort_index = argsort(tsq)[::-1]
r_index = argsort(sort_index)
for i in xrange(m):
for j in xrange(n):
n_false[j,i] = (tsqp[:,i]>tsq[j]).sum()
fp = loc_method(n_false,1)
n_signif = (arange(n) + 1.0)[r_index]
fd_rate = fp/n_signif
return fd_rate

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@ -4,15 +4,21 @@ There is almost no typechecking of any kind here, just focus on speed
"""
import math
import warnings
from scipy.linalg import svd,inv
from scipy import dot,empty,eye,newaxis,zeros,sqrt,diag,\
apply_along_axis,mean,ones,randn,empty_like,outer,r_,c_,\
rand,sum,cumsum,matrix, expand_dims,minimum,where,arange
has_sym=True
rand,sum,cumsum,matrix, expand_dims,minimum,where,arange,inner,tile
has_sym = True
has_arpack = True
try:
from symeig import symeig
except:
has_sym = False
try:
from scipy.sandbox import arpack
except:
has_arpack = False
def pca(a, aopt,scale='scores',mode='normal',center_axis=0):
@ -45,7 +51,6 @@ def pca(a, aopt,scale='scores',mode='normal',center_axis=0):
Notes
-----
Uses kernel speed-up if m>>n or m<<n.
If residuals turn rank deficient, a lower number of component than given
@ -101,6 +106,7 @@ def pca(a, aopt,scale='scores',mode='normal',center_axis=0):
else:
# residuals
E = a - dot(T, P.T)
#E = a
SEP = E**2
ssq = [SEP.sum(0), SEP.sum(1)]
# leverages
@ -256,7 +262,8 @@ def pls(a, b, aopt=2, scale='scores', mode='normal', center_axis=-1, ab=None):
Q = empty((l, aopt))
T = empty((m, aopt))
B = empty((aopt, n, l))
tt = empty((aopt,))
if ab==None:
ab = dot(a.T, b)
for i in range(aopt):
@ -265,10 +272,10 @@ def pls(a, b, aopt=2, scale='scores', mode='normal', center_axis=-1, ab=None):
w = w/vnorm(w)
elif n<l: # more yvars than xvars
if has_sym:
s, u = symeig(dot(ab, ab.T),range=[l,l],overwrite=True)
s, w = symeig(dot(ab, ab.T),range=[n,n],overwrite=True)
else:
u, s, vh = svd(dot(ab, ab.T))
w = u[:,0]
w, s, vh = svd(dot(ab, ab.T))
w = w[:,:1]
else: # standard wide xdata
if has_sym:
s, q = symeig(dot(ab.T, ab),range=[l,l],overwrite=True)
@ -283,16 +290,16 @@ def pls(a, b, aopt=2, scale='scores', mode='normal', center_axis=-1, ab=None):
r = r - dot(P[:,j].T, w)*R[:,j][:,newaxis]
t = dot(a, r)
tt = vnorm(t)**2
p = dot(a.T, t)/tt
q = dot(r.T, ab).T/tt
ab = ab - dot(p, q.T)*tt
tt[i] = tti = dot(t.T, t).ravel()
p = dot(a.T, t)/tti
q = dot(r.T, ab).T/tti
ab = ab - dot(p, q.T)*tti
T[:,i] = t.ravel()
W[:,i] = w.ravel()
if mode=='fast' and i==aopt-1:
if scale=='loads':
tnorm = apply_along_axis(vnorm, 0, T)
tnorm = sqrt(tt)
T = T/tnorm
W = W*tnorm
return {'T':T, 'W':W}
@ -300,26 +307,54 @@ def pls(a, b, aopt=2, scale='scores', mode='normal', center_axis=-1, ab=None):
P[:,i] = p.ravel()
R[:,i] = r.ravel()
Q[:,i] = q.ravel()
B[i] = dot(R[:,:i+1], Q[:,:i+1].T)
#B[i] = dot(R[:,:i+1], Q[:,:i+1].T)
qnorm = apply_along_axis(vnorm, 0, Q)
tnorm = sqrt(tt)
pp = (P**2).sum(0)
if mode=='detailed':
E = empty((aopt, m, n))
F = empty((aopt, k, l))
for i in range(1, aopt+1, 1):
E[i-1] = a - dot(T[:,:i], P[:,:i].T)
ssqx, ssqy = [], []
leverage = empty((aopt, m))
h2x = [] #hotellings T^2
h2y = []
for ai in range(aopt):
E[ai,:,:] = a - dot(T[:,:ai+1], P[:,:ai+1].T)
F[i-1] = b - dot(T[:,:i], Q[:,:i].T)
ssqx.append([(E[ai,:,:]**2).mean(0), (E[ai,:,:]**2).mean(1)])
ssqy.append([(F[ai,:,:]**2).mean(0), (F[ai,:,:]**2).mean(1)])
leverage[ai,:] = 1./m + ((T[:,:ai+1]/tnorm[:ai+1])**2).sum(1)
h2y.append(1./k + ((Q[:,:ai+1]/qnorm[:ai+1])**2).sum(1))
else:
E = a - dot(T[:,:aopt], P[:,:aopt].T)
F = b - dot(T[:,:aopt], Q[:,:aopt].T)
# residuals
E = a - dot(T, P.T)
F = b - dot(T, Q.T)
sepx = E**2
ssqx = [sepx.sum(0), sepx.sum(1)]
sepy = F**2
ssqy = [sepy.sum(0), sepy.sum(1)]
# leverage
leverage = 1./m + ((T/tnorm)**2).sum(1)
h2x = []
h2y = []
# variances
tp= tt*pp
tq = tt*qnorm*qnorm
expvarx = r_[0, 100*tp/(a*a).sum()]
expvary = r_[0, 100*tq/(b*b).sum()]
if scale=='loads':
tnorm = apply_along_axis(vnorm, 0, T)
T = T/tnorm
W = W*tnorm
Q = Q*tnorm
P = P*tnorm
return {'B':B, 'Q':Q, 'P':P, 'T':T, 'W':W, 'R':R, 'E':E, 'F':F}
return {'Q':Q, 'P':P, 'T':T, 'W':W, 'R':R, 'E':E, 'F':F,
'expvarx':expvarx, 'expvary':expvary, 'ssqx':ssqx, 'ssqy':ssqy,
'leverage':leverage, 'h2':h2x}
def w_simpls(aat, b, aopt):
""" Simpls for wide matrices.
@ -423,16 +458,6 @@ def bridge(a, b, aopt, scale='scores', mode='normal', r=0):
else: #normal
F = b - dot(a, B[-1])
E = a - dot(T, W.T)
# leverages
# fixme: probably need an orthogonal basis for row-space leverage
# T (scores) are not orthogonal
# Using a qr decomp to get an orthonormal basis for row-space
#Tq = qr(T)[0]
#s_lev,v_lev = leverage(aopt,Tq,W)
# explained variance
#var_x, exp_var_x = variances(a,T,W)
#qnorm = apply_along_axis(norm, 0, Q)
#var_y, exp_var_y = variances(b,U,Q/qnorm)
if scale=='loads':
T = T/tnorm
@ -442,7 +467,7 @@ def bridge(a, b, aopt, scale='scores', mode='normal', r=0):
return {'B':B, 'W':W, 'T':T, 'Q':Q, 'E':E, 'F':F, 'U':U, 'P':W}
def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], mode='normal', scale='scores', verbose=False):
def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], scale='scores', verbose=False):
""" L-shaped Partial Least Sqaures Regression by the nipals algorithm.
(X!Z)->Y
@ -464,6 +489,9 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], mode='normal', sca
evx : X-explained variance
evy : Y-explained variance
evz : Z-explained variance
mnx : X location
mny : Y location
mnz : Z location
:Notes:
@ -471,12 +499,12 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], mode='normal', sca
if mean_ctr!=None:
xctr, yctr, zctr = mean_ctr
X, mnX = center(X, xctr)
Y, mnY = center(Y, 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()
varX = (X**2).sum()
varY = (Y**2).sum()
varZ = (Z**2).sum()
m, n = X.shape
k, l = Y.shape
@ -491,36 +519,40 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], mode='normal', sca
K = empty((o, a_max))
L = empty((u, a_max))
B = empty((a_max, n, l))
b0 = empty((a_max, m, l))
#b0 = empty((a_max, 1, l))
var_x = empty((a_max,))
var_y = empty((a_max,))
var_z = empty((a_max,))
MAX_ITER = 250
LIM = 1e-1
for a in range(a_max):
if verbose:
print "\n Working on comp. %s" %a
print "\nWorking on comp. %s" %a
u = Y[:,:1]
diff = 1
MAX_ITER = 200
lim = 1e-16
niter = 0
while (diff>lim and niter<MAX_ITER):
while (diff>LIM and niter<MAX_ITER):
niter += 1
u1 = u.copy()
w = dot(X.T, u)
w = w/sqrt(dot(w.T, w))
#w = w/dot(w.T, w)
l = dot(Z, w)
k = dot(Z.T, l)
k = k/sqrt(dot(k.T, k))
#k = k/dot(k.T, k)
w = alpha*k + (1-alpha)*w
#print sqrt(dot(w.T, 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()
diff = dot((u-u1).T, (u-u1))
if verbose:
print "Converged after %s iterations" %niter
print "Error: %.2E" %diff
tt = dot(t.T, t)
p = dot(X.T, t)/tt
q = dot(Y.T, t)/tt
@ -543,7 +575,8 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], mode='normal', sca
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])
#b0[a] = mnY - dot(mnX, B[a])
# variance explained
evx = 100.0*(1 - var_x/varX)
@ -558,7 +591,7 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 1], mode='normal', sca
L = L*knorm
K = K/knorm
return {'T':T, 'W':W, 'P':P, 'Q':Q, 'U':U, 'L':L, 'K':K, 'B':B, 'b0':b0, 'evx':evx, 'evy':evy, 'evz':evz}
return {'T':T, 'W':W, 'P':P, 'Q':Q, 'U':U, 'L':L, 'K':K, 'B':B, 'evx':evx, 'evy':evy, 'evz':evz,'mnx': mnX, 'mny': mnY, 'mnz': mnZ}
@ -670,7 +703,8 @@ def nipals_pls(X, Y, a_max, alpha=.7, ax_center=0, mode='normal', scale='scores'
W = W*tnorm
Q = Q*tnorm
return {'T':T, 'W':W, 'P':P, 'Q':Q, 'U':U, 'B':B, 'b0':b0, 'evx':evx, 'evy':evy}
return {'T':T, 'W':W, 'P':P, 'Q':Q, 'U':U, 'B':B, 'b0':b0, 'evx':evx, 'evy':evy,
'mnx': mnX, 'mny': mnY, 'xc': X, 'yc': Y}
########### Helper routines #########
@ -691,6 +725,11 @@ def esvd(data, amax=None):
m, n = data.shape
if m>=n:
kernel = dot(data.T, data)
if has_arpack:
if amax==None:
amax = n
s, v = arpack.eigen_symmetric(kernel,k=amax, which='LM',
maxiter=200,tol=1e-5)
if has_sym:
if amax==None:
amax = n
@ -728,16 +767,34 @@ def vnorm(x):
return math.sqrt(dot(x.T, x))
def center(a, axis):
# 0 = col center, 1 = row center, 2 = double center
# -1 = nothing
# 0 = col center, 1 = row center, 2 = double center
# -1 = nothing
# check if we have a vector
is_vec = len(a.shape)==1
if not is_vec:
is_vec = a.shape[0]==1 or a.shape[1]==1
if is_vec:
if axis==2:
warnings.warn("Double centering of vecor ignored, using ordinary centering")
if axis==-1:
mn = 0
else:
mn = a.mean()
return a - mn, mn
# !!!fixme: use broadcasting
if axis==-1:
mn = zeros((a.shape[1],))
mn = zeros((1,a.shape[1],))
#mn = tile(mn, (a.shape[0], 1))
elif axis==0:
mn = a.mean(0)
mn = a.mean(0)[newaxis]
#mn = tile(mn, (a.shape[0], 1))
elif axis==1:
mn = a.mean(1)[:,newaxis]
#mn = tile(mn, (1, a.shape[1]))
elif axis==2:
mn = a.mean(0) + a.mean(1)[:,newaxis] - a.mean()
mn = a.mean(0)[newaxis] + a.mean(1)[:,newaxis] - a.mean()
return a - mn , a.mean(0)[newaxis]
else:
raise IOError("input error: axis must be in [-1,0,1,2]")
@ -755,3 +812,64 @@ def scale(a, axis):
return a - sc, sc
## #PCA CALCS
## % Calculate Q limit using unused eigenvalues
## temp = diag(s);
## if n < m
## emod = temp(lv+1:n,:);
## else
## emod = temp(lv+1:m,:);
## end
## th1 = sum(emod);
## th2 = sum(emod.^2);
## th3 = sum(emod.^3);
## h0 = 1 - ((2*th1*th3)/(3*th2^2));
## if h0 <= 0.0
## h0 = .0001;
## disp(' ')
## disp('Warning: Distribution of unused eigenvalues indicates that')
## disp(' you should probably retain more PCs in the model.')
## end
## q = th1*(((1.65*sqrt(2*th2*h0^2)/th1) + 1 + th2*h0*(h0-1)/th1^2)^(1/h0));
## disp(' ')
## disp('The 95% Q limit is')
## disp(q)
## if plots >= 1
## lim = [q q];
## plot(scl,res,scllim,lim,'--b')
## str = sprintf('Process Residual Q with 95 Percent Limit Based on %g PC Model',lv);
## title(str)
## xlabel('Sample Number')
## ylabel('Residual')
## pause
## end
## % Calculate T^2 limit using ftest routine
## if lv > 1
## if m > 300
## tsq = (lv*(m-1)/(m-lv))*ftest(.95,300,lv,2);
## else
## tsq = (lv*(m-1)/(m-lv))*ftest(.95,m-lv,lv,2);
## end
## disp(' ')
## disp('The 95% T^2 limit is')
## disp(tsq)
## % Calculate the value of T^2 by normalizing the scores to
## % unit variance and summing them up
## if plots >= 1.0
## temp2 = scores*inv(diag(ssq(1:lv,2).^.5));
## tsqvals = sum((temp2.^2)');
## tlim = [tsq tsq];
## plot(scl,tsqvals,scllim,tlim,'--b')
## str = sprintf('Value of T^2 with 95 Percent Limit Based on %g PC Model',lv);
## title(str)
## xlabel('Sample Number')
## ylabel('Value of T^2')
## end
## else
## disp('T^2 not calculated when number of latent variables = 1')
## tsq = 1.96^2;
## end

View File

@ -1,7 +1,7 @@
"""This module implements some common validation schemes from pca and pls.
"""
from scipy import ones,mean,sqrt,dot,newaxis,zeros,sum,empty,\
apply_along_axis,eye,kron,array,sort,zeros_like,argmax
apply_along_axis,eye,kron,array,sort,zeros_like,argmax,atleast_2d
from scipy.stats import median
from scipy.linalg import triu,inv,svd,norm
@ -9,7 +9,7 @@ from select_generators import w_pls_gen,w_pls_gen_jk,pls_gen,pca_gen,diag_pert
from engines import w_simpls,pls,bridge,pca,nipals_lpls
from cx_utils import m_shape
def w_pls_cv_val(X, Y, amax, n_blocks=None, algo='simpls'):
def w_pls_cv_val(X, Y, amax, n_blocks=None):
"""Returns rmsep and aopt for pls tailored for wide X.
The root mean square error of cross validation is calculated
@ -62,12 +62,10 @@ def w_pls_cv_val(X, Y, amax, n_blocks=None, algo='simpls'):
for Din, Doi, Yin, Yout in V:
ym = -sum(Yout, 0)[newaxis]/(1.0*Yin.shape[0])
PRESS[:,0] = PRESS[:,0] + ((Yout - ym)**2).sum(0)
if algo=='simpls':
dat = w_simpls(Din, Yin, amax)
Q, U, H = dat['Q'], dat['U'], dat['H']
That = dot(Doi, dot(U, inv(triu(dot(H.T, U))) ))
else:
raise NotImplementedError
dat = w_simpls(Din, Yin, amax)
Q, U, H = dat['Q'], dat['U'], dat['H']
That = dot(Doi, dot(U, inv(triu(dot(H.T, U))) ))
Yhat = []
for j in range(l):
@ -78,7 +76,7 @@ def w_pls_cv_val(X, Y, amax, n_blocks=None, algo='simpls'):
#Yhat = Yin - dot(That,Q.T)
msep = PRESS/(Y.shape[0])
aopt = find_aopt_from_sep(msep)
return sqrt(msep)
return sqrt(msep), aopt
def pls_val(X, Y, amax=2, n_blocks=10, algo='pls'):
k, l = m_shape(Y)
@ -108,29 +106,54 @@ def pls_val(X, Y, amax=2, n_blocks=10, algo='pls'):
aopt = find_aopt_from_sep(msep)
return msep, Yhat, aopt
def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5):
def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5, mean_ctr=[2,0,2]):
"""Performs crossvalidation to get generalisation error in lpls"""
assert(nsets<=X.shape[0])
cv_iter = pls_gen(X, Y, n_blocks=nsets,center=False,index_out=True)
k, l = Y.shape
Yhat = empty((a_max,k,l), 'd')
Yc = empty((k, l), 'd')
Yhat = empty((a_max, k, l), 'd')
Yhatc = empty((a_max, k, l), 'd')
sep2 = empty((a_max, k, l), 'd')
for i, (xcal,xi,ycal,yi,ind) in enumerate(cv_iter):
dat = nipals_lpls(xcal,ycal,Z,
a_max=a_max,
alpha=alpha,
mean_ctr=[2,0,1],
mean_ctr=mean_ctr,
verbose=False)
B = dat['B']
b0 = dat['b0']
#b0 = dat['b0']
for a in range(a_max):
Yhat[a,ind,:] = b0[a][0][0] + dot(xi-xcal.mean(0), 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')
if mean_ctr[0] in [0, 2]:
xi = xi - dat['mnx']
else:
xi = xi - xi.mean(1)[:,newaxis] #???: cheating?
if mean_ctr[1] in [0, 2]:
ym = dat['mny']
else:
ym = yi.mean(1)[:,newaxis] #???: check this
Yhat[a,ind,:] = atleast_2d(ym + dot(xi, B[a]))
#Yhat[a,ind,:] = atleast_2d(b0[a] + dot(xi, B[a]))
# todo: need a better support for class validation
y_is_class = Y.dtype.char.lower() in ['i','p', 'b', 'h','?']
print Y.dtype.char
if y_is_class:
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))
rmsep = sqrt(sep.mean(1)).T
#rmsep2 = sqrt(sep2.mean(1))
aopt = find_aopt_from_sep(rmsep)
return rmsep, Yhat, aopt
def pca_alter_val(a, amax, n_sets=10, method='diag'):
@ -247,7 +270,7 @@ def pca_jkP(a, aopt, n_blocks=None):
return PP
def lpls_jk(X, Y, Z, a_max, nsets=None, alpha=.5):
def lpls_jk(X, Y, Z, a_max, nsets=None, xz_alpha=.5, mean_ctr=[2,0,2]):
cv_iter = pls_gen(X, Y, n_blocks=nsets,center=False,index_out=False)
m, n = X.shape
k, l = Y.shape
@ -258,8 +281,8 @@ def lpls_jk(X, Y, Z, a_max, nsets=None, alpha=.5):
WWz = empty((nsets, o, a_max), 'd')
#WWy = empty((nsets, l, a_max), 'd')
for i, (xcal,xi,ycal,yi) in enumerate(cv_iter):
dat = nipals_lpls(xcal,ycal,Z,a_max=a_max,alpha=alpha,
mean_ctr=[2,0,1],scale='loads',verbose=False)
dat = nipals_lpls(xcal,ycal,Z,a_max=a_max,alpha=xz_alpha,
mean_ctr=mean_ctr,scale='loads',verbose=False)
WWx[i,:,:] = dat['W']
WWz[i,:,:] = dat['L']
#WWy[i,:,:] = dat['Q']