Mostly clean ups
This commit is contained in:
parent
2951ca4088
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4c809674bb
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@ -12,7 +12,7 @@ from numpy.random import shuffle
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from engines import nipals_lpls as lpls
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def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5, mean_ctr=[2,0,2], zorth=False, verbose=True):
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def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5, mean_ctr=[2,0,2], zorth=False, verbose=False):
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"""Performs crossvalidation for generalisation error in lpls.
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The L-PLS crossvalidation is estimated just like an ordinary pls
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@ -61,8 +61,8 @@ def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5, mean_ctr=[2,0,2], zorth=Fals
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m, n = X.shape
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k, l = Y.shape
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o, p = Z.shape
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assert m==k, "X (%d,%d) - Y (%d,%d) dim mismatch" %(m,n,k,l)
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assert n==p, "X (%d,%d) - Z (%d,%d) dim mismatch" %(m,n,o,p)
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assert m == k, "X (%d,%d) - Y (%d,%d) dim mismatch" %(m, n, k, l)
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assert n == p, "X (%d,%d) - Z (%d,%d) dim mismatch" %(m, n, o, p)
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if nsets == None:
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nsets = m
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if nsets > X.shape[0]:
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@ -80,11 +80,11 @@ def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5, mean_ctr=[2,0,2], zorth=Fals
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if mean_ctr[0] != 1:
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xi = X[val,:] - dat['mnx']
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else:
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xi = X[val] - X[val].mean(1)[:,newaxis]
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xi = X[val] - X[cal].mean(1)[:,newaxis]
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if mean_ctr[2] != 1:
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ym = dat['mny']
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else:
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ym = Y[val].mean(1)[:,newaxis] #???: check this
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ym = Y[cal].mean(1)[:,newaxis]
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# predictions
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for a in range(a_max):
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Yhat[a,val,:] = atleast_2d(ym + dot(xi, dat['B'][a]))
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@ -113,7 +113,7 @@ def lpls_val(X, Y, Z, a_max=2, nsets=None,alpha=.5, mean_ctr=[2,0,2], zorth=Fals
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def pca_jk(a, aopt, n_blocks=None):
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"""Returns jack-knife segements from PCA.
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Parameters:
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*Parameters*:
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a : {array}
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data matrix (n x m)
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@ -122,20 +122,14 @@ def pca_jk(a, aopt, n_blocks=None):
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nsets : {integer}
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number of segments
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Returns:
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*Returns*:
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Pcv : {array}
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Loadings collected in a three way matrix (n_segments, m, aopt)
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Notes:
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- The loadings are scaled with the (1/samples)*eigenvalues.
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*Notes*:
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- Crossvalidation method is currently set to random blocks of samples.
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- todo: add support for T
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- fixme: more efficient to add this in validation loop?
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"""
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if nsets == None:
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@ -183,7 +177,7 @@ def pls_jk(X, Y, a_opt, nsets=None, center=True, verbose=False):
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"""
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m, n = X.shape
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k, l = Y.shape
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assert(m==k)
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assert(m == k)
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if nsets == None:
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nsets = X.shape[0]
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Wcv = empty((nsets, X.shape[1], a_opt), dtype=X.dtype)
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@ -242,9 +236,9 @@ def lpls_jk(X, Y, Z, a_opt, nsets=None, xz_alpha=.5, mean_ctr=[2,0,2], verbose=F
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m, n = X.shape
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k, l = Y.shape
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o, p = Z.shape
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assert(m==k)
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assert(n==p)
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if nsets==None:
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assert(m == k)
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assert(n == p)
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if nsets == None:
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nsets = m
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WWx = empty((nsets, n, a_opt), 'd')
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WWz = empty((nsets, o, a_opt), 'd')
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@ -279,12 +273,12 @@ def find_aopt_from_sep(sep, method='vanilla'):
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A guess on the optimal number of components
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"""
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if method=='vanilla':
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if method == 'vanilla':
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# min rmsep
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rmsecv = sqrt(sep.mean(0))
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return rmsecv.argmin() + 1
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elif method=='75perc':
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elif method == '75perc':
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prct = .75 #percentile
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ind = 1.*sep.shape[0]*prct
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med = median(sep)
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@ -305,6 +299,7 @@ def cv(N, K, randomise=True, sequential=False):
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of length ~N/K, *without* replacement.
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*Parameters*:
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N : {integer}
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Total number of samples
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K : {integer}
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@ -333,7 +328,7 @@ def cv(N, K, randomise=True, sequential=False):
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otherwise interleaved ordering is used.
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"""
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if N>K:
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if N > K:
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raise ValueError, "You cannot divide a list of %d samples into more than %d segments. Yout tried: %s" %(K, K, N)
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index = xrange(N)
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if randomise:
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145
pyblm/engines.py
145
pyblm/engines.py
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@ -9,16 +9,17 @@ from math import sqrt as msqrt
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from numpy import dot,empty,zeros,apply_along_axis,newaxis,finfo,sqrt,r_,expand_dims,\
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minimum
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from numpy.linalg import inv, svd
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from numpy.linalg import inv,svd
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from scipy.sandbox import arpack
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def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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""" Principal Component Analysis.
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PCA is a low rank bilinear aprroximation to a data matrix that sequentially
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extracts orthogonal components of maximum variance.
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Parameters:
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*Parameters*:
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X : {array}
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Data measurement matrix, (samples x variables)
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@ -27,7 +28,7 @@ def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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center_axis : {integer}
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Center along given axis. If neg.: no centering (-inf,..., matrix modes)
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Returns:
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*Returns*:
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T : {array}
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Scores, (samples, components)
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@ -47,7 +48,7 @@ def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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leverage : {array}
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Leverages, (samples,)
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OtherParameters:
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*OtherParameters*:
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scale : {string}, optional
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Where to put the weights [['scores'], 'loadings']
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@ -55,7 +56,7 @@ def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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Amount of info retained, [['normal'], 'fast', 'detailed']
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:SeeAlso:
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*SeeAlso*:
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`center` : Data centering
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@ -78,10 +79,12 @@ def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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"""
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m, n = X.shape
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assert(aopt<=min(m,n))
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if center_axis>=0:
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min_aopt = min(m, n)
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if center_axis >= 0:
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X = X - expand_dims(X.mean(center_axis), center_axis)
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if m>(n+100) or n>(m+100):
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min_aopt = min_aopt - 1
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assert(aopt <= min_aopt)
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if m > (n+100) or n > (m+100):
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u, s, v = esvd(X, aopt)
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else:
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u, s, vt = svd(X, 0)
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@ -92,7 +95,7 @@ def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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# ranktest
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tol = 1e-10
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eff_rank = sum(s>s[0]*tol)
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eff_rank = sum(s > s[0]*tol)
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aopt = minimum(aopt, eff_rank)
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T = u*s
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s = s[:aopt]
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@ -124,7 +127,7 @@ def pca(X, aopt, scale='scores', mode='normal', center_axis=0):
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sep = E**2
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ssq = [sep.sum(0), sep.sum(1)]
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# leverages
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if scale=='loads':
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if scale == 'loads':
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lev = [(1./m)+(T**2).sum(1), (1./n)+((P/s)**2).sum(1)]
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else:
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lev = [(1./m)+((T/s)**2).sum(1), (1./n)+(P**2).sum(1)]
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@ -139,7 +142,7 @@ def pcr(a, b, aopt, scale='scores',mode='normal',center_axis=0):
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Performs PCR on given matrix and returns results in a dictionary.
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Parameters:
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*Parameters*:
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a : array
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Data measurement matrix, (samples x variables)
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@ -148,19 +151,19 @@ def pcr(a, b, aopt, scale='scores',mode='normal',center_axis=0):
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aopt : int
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Number of components to use, aopt<=min(samples, variables)
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Returns:
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*Returns*:
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results : dict
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keys -- values, T -- scores, P -- loadings, E -- residuals,
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levx -- leverages, ssqx -- sum of squares, expvarx -- cumulative
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explained variance, aopt -- number of components used
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OtherParameters:
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*OtherParameters*:
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mode : str
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Amount of info retained, ('fast', 'normal', 'detailed')
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center_axis : int
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Center along given axis. If neg.: no centering (-inf,..., matrix modes)
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mode : {string}
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Amount of info retained, ('fast', 'normal', 'detailed')
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center_axis : {integer}
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Center along given axis. If neg.: no centering (-inf,..., matrix modes)
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SeeAlso:
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@ -194,21 +197,21 @@ def pcr(a, b, aopt, scale='scores',mode='normal',center_axis=0):
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except:
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b = atleast_2d(b).T
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k, l = b.shape
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if center_axis>=0:
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if center_axis >= 0:
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b = b - expand_dims(b.mean(center_axis), center_axis)
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dat = pca(a, aopt=aopt, scale=scale, mode=mode, center_axis=center_axis)
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T = dat['T']
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weights = apply_along_axis(vnorm, 0, T)**2
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if scale=='loads':
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if scale == 'loads':
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Q = dot(b.T, T*weights)
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else:
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Q = dot(b.T, T/weights)
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if mode=='fast':
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if mode == 'fast':
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dat.update({'Q':Q})
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return dat
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if mode=='detailed':
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if mode == 'detailed':
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F = empty((aopt, k, l))
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ssqy = []
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for i in range(aopt):
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@ -284,7 +287,7 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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*SeeAlso*:
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`center` : data centering
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`center` - data centering
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*Notes*
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@ -310,14 +313,16 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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except:
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Y = atleast_2d(Y).T
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k, l = Y.shape
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assert(m==k)
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assert(aopt<min(m, n))
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mnx, mny = 0,0
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if center_axis>=0:
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assert(m == k)
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mnx, mny = 0, 0
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min_aopt = min(m, n)
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if center_axis >= 0:
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mnx = expand_dims(X.mean(center_axis), center_axis)
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X = X - mnx
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min_aopt = min_aopt - 1
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mny = expand_dims(Y.mean(center_axis), center_axis)
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Y = Y - mny
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assert(aopt > 0 and aopt < min_aopt)
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W = empty((n, aopt))
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P = empty((n, aopt))
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@ -329,10 +334,10 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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XY = dot(X.T, Y)
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for i in range(aopt):
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if XY.shape[1]==1: #pls 1
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if XY.shape[1] == 1: #pls 1
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w = XY.reshape(n, l)
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w = w/vnorm(w)
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elif n<l: # more yvars than xvars
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elif n < l: # more yvars than xvars
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s, w = arpack.eigen_symmetric(dot(XY, XY.T),k=1, tol=1e-10, maxiter=100)
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#w, s, vh = svd(dot(XY, XY.T))
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#w = w[:,:1]
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@ -344,7 +349,7 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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w = dot(XY, q)
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w = w/vnorm(w)
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r = w.copy()
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if i>0:
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if i > 0:
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for j in range(0, i, 1):
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r = r - dot(P[:,j].T, w)*R[:,j][:,newaxis]
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@ -356,8 +361,8 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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T[:,i] = t.ravel()
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W[:,i] = w.ravel()
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if mode=='fast' and i==aopt-1:
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if scale=='loads':
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if mode == 'fast' and i == (aopt - 1):
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if scale == 'loads':
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tnorm = sqrt(tt)
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T = T/tnorm
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W = W*tnorm
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@ -371,7 +376,7 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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qnorm = apply_along_axis(vnorm, 0, Q)
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tnorm = sqrt(tt)
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pp = (P**2).sum(0)
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if mode=='detailed':
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if mode == 'detailed':
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E = empty((aopt, m, n))
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F = empty((aopt, k, l))
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ssqx, ssqy = [], []
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@ -401,7 +406,7 @@ def pls(X, Y, aopt=2, scale='scores', mode='normal', center_axis=-1):
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expvarx = r_[0, 100*tp/(X*X).sum()]
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expvary = r_[0, 100*tq/(Y*Y).sum()]
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if scale=='loads':
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if scale == 'loads':
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T = T/tnorm
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W = W*tnorm
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Q = Q*tnorm
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@ -495,11 +500,11 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 2], scale='scores', zo
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m, n = X.shape
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k, l = Y.shape
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u, o = Z.shape
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max_rank = min(m, n)
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assert (a_max>0 and a_max<max_rank), "Number of comp error:\
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tried:%d, max_rank:%d" %(a_max,max_rank)
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max_rank = min(m, n) + 1
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assert (a_max > 0 and a_max < max_rank), "Number of comp error:\
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tried: %d, max_rank: %d" %(a_max, max_rank)
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if mean_ctr!=None:
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if mean_ctr != None:
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xctr, yctr, zctr = mean_ctr
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X, mnX = center(X, xctr)
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Y, mnY = center(Y, yctr)
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@ -537,7 +542,7 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 2], scale='scores', zo
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l = G[:,:1]
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diff = 1
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niter = 0
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while (diff>LIM and niter<MAX_ITER):
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while (diff > LIM and niter < MAX_ITER):
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niter += 1
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u1 = u.copy()
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w1 = w.copy()
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@ -562,7 +567,7 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 2], scale='scores', zo
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u = dot(F, c)
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diff = dot((u - u1).T, (u - u1))
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if verbose:
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if niter==MAX_ITER:
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if niter == MAX_ITER:
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print "Maximum nunber of iterations reached!"
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print "Iterations: %d " %niter
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print "Error: %.2E" %diff
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@ -606,7 +611,7 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 2], scale='scores', zo
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evy = 100.*(1 - var_y/varY)
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evz = 100.*(1 - var_z/varZ)
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if scale=='loads':
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if scale == 'loads':
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tnorm = apply_along_axis(vnorm, 0, T)
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T = T/tnorm
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W = W*tnorm
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@ -617,6 +622,20 @@ def nipals_lpls(X, Y, Z, a_max, alpha=.7, mean_ctr=[2, 0, 2], scale='scores', zo
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return {'T':T, 'W':W, 'P':P, 'Q':Q, 'U':U, 'L':L, 'K':K, 'B':B, 'E': E, 'F': F, 'G': G, 'evx':evx, 'evy':evy, 'evz':evz,'mnx': mnX, 'mny': mnY, 'mnz': mnZ}
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def lpls_predict(model_dict, x, aopt):
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"""Predict lpls reponses from existing model on new data.
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"""
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try:
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m, n = x.shape
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except:
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x = atleast_2d(x.shape)
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m, n = x.shape
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if 'B0' in model_dict.keys():
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y = model_dict['B0'] + dot()
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def vnorm(a):
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"""Returns the norm of a vector.
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@ -654,28 +673,28 @@ def center(a, axis):
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"""
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# check if we have a vector
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is_vec = len(a.shape)==1
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is_vec = len(a.shape) == 1
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if not is_vec:
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is_vec = a.shape[0]==1 or a.shape[1]==1
|
||||
is_vec = a.shape[0] == 1 or a.shape[1] == 1
|
||||
if is_vec:
|
||||
if axis==2:
|
||||
if axis == 2:
|
||||
warnings.warn("Double centering of vecor ignored, using ordinary centering")
|
||||
if axis==-1:
|
||||
if axis == -1:
|
||||
mn = 0
|
||||
else:
|
||||
mn = a.mean()
|
||||
return a - mn, mn
|
||||
# !!!fixme: use broadcasting
|
||||
if axis==-1:
|
||||
if axis == -1:
|
||||
mn = zeros((1,a.shape[1],))
|
||||
#mn = tile(mn, (a.shape[0], 1))
|
||||
elif axis==0:
|
||||
elif axis == 0:
|
||||
mn = a.mean(0)[newaxis]
|
||||
#mn = tile(mn, (a.shape[0], 1))
|
||||
elif axis==1:
|
||||
elif axis == 1:
|
||||
mn = a.mean(1)[:,newaxis]
|
||||
#mn = tile(mn, (1, a.shape[1]))
|
||||
elif axis==2:
|
||||
elif axis == 2:
|
||||
mn = a.mean(0)[newaxis] + a.mean(1)[:,newaxis] - a.mean()
|
||||
return a - mn , a.mean(0)[newaxis]
|
||||
else:
|
||||
|
@ -702,11 +721,11 @@ def _scale(a, axis):
|
|||
Scaling vector/matrix
|
||||
"""
|
||||
|
||||
if axis==-1:
|
||||
if axis == -1:
|
||||
sc = zeros((a.shape[1],))
|
||||
elif axis==0:
|
||||
elif axis == 0:
|
||||
sc = a.std(0)
|
||||
elif axis==1:
|
||||
elif axis == 1:
|
||||
sc = a.std(1)[:,newaxis]
|
||||
else:
|
||||
raise IOError("input error: axis must be in [-1,0,1]")
|
||||
|
@ -714,19 +733,19 @@ def _scale(a, axis):
|
|||
return a - sc, sc
|
||||
|
||||
def esvd(data, a_max=None):
|
||||
""" SVD with kernel calculation
|
||||
"""SVD with kernel calculation.
|
||||
|
||||
Calculate subspaces of X'X or XX' depending on the shape
|
||||
of the matrix.
|
||||
|
||||
Parameters:
|
||||
*Parameters*:
|
||||
|
||||
data : {array}
|
||||
Data matrix
|
||||
a_max : {integer}
|
||||
Number of components to extract
|
||||
|
||||
Returns:
|
||||
*Returns*:
|
||||
|
||||
u : {array}
|
||||
Right hand eigenvectors
|
||||
|
@ -735,20 +754,20 @@ def esvd(data, a_max=None):
|
|||
v : {array}
|
||||
Left hand eigenvectors
|
||||
|
||||
notes:
|
||||
*Notes*:
|
||||
|
||||
Uses Anoldi iterations (ARPACK)
|
||||
Uses Anoldi iterations for the symmetric eigendecomp (ARPACK)
|
||||
|
||||
"""
|
||||
|
||||
m, n = data.shape
|
||||
if m>=n:
|
||||
if m >= n:
|
||||
kernel = dot(data.T, data)
|
||||
|
||||
if a_max==None:
|
||||
if a_max == None:
|
||||
a_max = n - 1
|
||||
s, v = arpack.eigen_symmetric(kernel,k=a_max, which='LM',
|
||||
maxiter=200,tol=1e-5)
|
||||
s, v = arpack.eigen_symmetric(kernel, k=a_max, which='LM',
|
||||
maxiter=200, tol=1e-5)
|
||||
s = s[::-1]
|
||||
v = v[:,::-1]
|
||||
#u, s, vt = svd(kernel)
|
||||
|
@ -757,10 +776,10 @@ def esvd(data, a_max=None):
|
|||
u = dot(data, v)/s
|
||||
else:
|
||||
kernel = dot(data, data.T)
|
||||
if a_max==None:
|
||||
if a_max == None:
|
||||
a_max = m -1
|
||||
s, u = arpack.eigen_symmetric(kernel,k=a_max, which='LM',
|
||||
maxiter=200,tol=1e-5)
|
||||
s, u = arpack.eigen_symmetric(kernel, k=a_max, which='LM',
|
||||
maxiter=200, tol=1e-5)
|
||||
s = s[::-1]
|
||||
u = u[:,::-1]
|
||||
#u, s, vt = svd(kernel)
|
||||
|
|
Reference in New Issue