修訂. | d1bd54aad8204ba385a9b1e6d913dbe43b55d86d |
---|---|
大小 | 4,709 bytes |
時間 | 2011-03-16 06:50:44 |
作者 | lorenzo |
Log Message | I added a code to calculate the anisotropy coefficients of a cluster. |
#! /usr/bin/env python
# from enthought.mayavi import mlab
import scipy as s
import numpy as n
import scipy.linalg as sl
import sys
def inertia_tensor(cluster):
x=cluster[:,0]
y=cluster[:,1]
z=cluster[:,2]
oneone=s.sum(y**2.+z**2.)
onetwo=-s.sum(x*y)
onethree=-s.sum(x*z)
twoone= -s.sum(x*y)
twotwo=s.sum(x**2.+z**2.)
twothree=-s.sum(y*z)
threeone=-s.sum(x*z)
threetwo=-s.sum(y*z)
threethree=s.sum(x**2.+y**2.)
my_mat=s.zeros(9).reshape((3,3))
my_mat[0,0]=oneone
my_mat[0,1]=onetwo
my_mat[0,2]=onethree
my_mat[1,0]=twoone
my_mat[1,1]=twotwo
my_mat[1,2]=twothree
my_mat[2,0]=threeone
my_mat[2,1]=threetwo
my_mat[2,2]=threethree
return my_mat
def find_CM(cluster):
CM=s.mean(cluster, axis=0)
return CM
def relocate_cluster(cluster):
cluster_shift=find_CM(cluster)
cluster[:,0]=cluster[:,0]-cluster_shift[0]
cluster[:,1]=cluster[:,1]-cluster_shift[1]
cluster[:,2]=cluster[:,2]-cluster_shift[2]
return cluster
def move_cluster(cluster, vector):
cluster_new=s.copy(cluster)
cluster_new[:,0]=cluster_new[:,0]+vector[0]
cluster_new[:,1]=cluster_new[:,1]+vector[1]
cluster_new[:,2]=cluster_new[:,2]+vector[2]
return cluster_new
def calc_rg(cluster):
x=cluster[:,0]
y=cluster[:,1]
z=cluster[:,2]
rg=s.var(x)+s.var(y)+s.var(z)
rg=s.sqrt(rg)
return rg
def euclidean_distances(X, Y, Y_norm_squared=None, squared=False):
"""
Considering the rows of X (and Y=X) as vectors, compute the
distance matrix between each pair of vectors.
Parameters
----------
X: array of shape (n_samples_1, n_features)
Y: array of shape (n_samples_2, n_features)
Y_norm_squared: array [n_samples_2], optional
pre-computed (Y**2).sum(axis=1)
squared: boolean, optional
This routine will return squared Euclidean distances instead.
Returns
-------
distances: array of shape (n_samples_1, n_samples_2)
Examples
--------
>>> from scikits.learn.metrics.pairwise import euclidean_distances
>>> X = [[0, 1], [1, 1]]
>>> # distrance between rows of X
>>> euclidean_distances(X, X)
array([[ 0., 1.],
[ 1., 0.]])
>>> # get distance to origin
>>> euclidean_distances(X, [[0, 0]])
array([[ 1. ],
[ 1.41421356]])
"""
# should not need X_norm_squared because if you could precompute that as
# well as Y, then you should just pre-compute the output and not even
# call this function.
if X is Y:
X = Y = n.asanyarray(X)
else:
X = n.asanyarray(X)
Y = n.asanyarray(Y)
if X.shape[1] != Y.shape[1]:
raise ValueError("Incompatible dimension for X and Y matrices")
XX = n.sum(X * X, axis=1)[:, n.newaxis]
if X is Y: # shortcut in the common case euclidean_distances(X, X)
YY = XX.T
elif Y_norm_squared is None:
YY = Y.copy()
YY **= 2
YY = n.sum(YY, axis=1)[n.newaxis, :]
else:
YY = n.asanyarray(Y_norm_squared)
if YY.shape != (Y.shape[0],):
raise ValueError("Incompatible dimension for Y and Y_norm_squared")
YY = YY[n.newaxis, :]
# TODO:
# a faster cython implementation would do the dot product first,
# and then add XX, add YY, and do the clipping of negative values in
# a single pass over the output matrix.
distances = XX + YY # Using broadcasting
distances -= 2 * n.dot(X, Y.T)
distances = n.maximum(distances, 0)
if squared:
return distances
else:
return n.sqrt(distances)
######################################################################
kf=1.
df= 1.78 # 1.8
print sys.argv
if (len(sys.argv)==2):
prefix="aggregate_number_"
middle=sys.argv[-1]
filename="_.dat"
filename=prefix+middle+filename
elif (len(sys.argv)==3):
prefix="aggregate_number_"
middle=sys.argv[-2]
prefix2="_generation_"
middle2=sys.argv[-1]
filename="_.dat"
filename=prefix+middle+prefix2+middle2+filename
final_cluster=n.loadtxt(filename)
N=len(final_cluster[:,0])
print "N is, ", N
#ensure its CM is in (0,0,0)
final_cluster=relocate_cluster(final_cluster)
inertia_mat=inertia_tensor(final_cluster)
print "inertia_mat is, ", inertia_mat
eigenvalues=s.real(sl.eigvals(inertia_mat)/N)
eigenvalues=s.sort(eigenvalues)[::-1]
print "eigenvalues are, ", eigenvalues
r123=s.sqrt(eigenvalues)
print "r123, ", r123
Rg=calc_rg(final_cluster)
print "Rg is, ", Rg
print "Rg**2. is, ", Rg**2.
print "0.5*(sum(r123**2.)) is, ", 0.5*(sum(r123**2.))
anisotropy=s.zeros(2)
anisotropy[0]=eigenvalues[0]/eigenvalues[2]
anisotropy[1]=eigenvalues[1]/eigenvalues[2]
print "anisotropy is, ", anisotropy
print "So far so good"