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dft_tools/pytriqs/dos/dos.py
Michel Ferrero f7fad85fca Iteration over the doc
This is an iteration over the doc mainly thank to Priyanka.
I fixed another couple of details on the way.
2013-12-31 14:22:00 +01:00

191 lines
6.6 KiB
Python

################################################################################
#
# TRIQS: a Toolbox for Research in Interacting Quantum Systems
#
# Copyright (C) 2011 by M. Ferrero, O. Parcollet
#
# TRIQS is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# TRIQS. If not, see <http://www.gnu.org/licenses/>.
#
################################################################################
import types,string,itertools
from operator import isSequenceType
import numpy
class DOS :
r"""
* Stores a density of state of fermions
.. math::
\rho (\epsilon) \equiv \sum'_k \delta( \epsilon - \epsilon_k)
* The sum is normalized
.. math::
\int_{-\infty}^{\infty} d\epsilon \rho (\epsilon) = 1
* Implement :ref:`Plot Protocol <plotting>`.
"""
def __init__(self, eps, rho, name = ''):
"""
Parameters
------------
eps : 1d array-type
eps[i] is value of epsilon.
rho : 1d array-type
The corresponding value of the dos.
name : string
Name of the dos/orbital
"""
self.name = name
try :
self.eps = numpy.array( eps )
assert len(self.eps.shape) ==1
except :
raise RuntimeError, "Argument eps mismatch"
try :
self.rho = numpy.array( rho )
assert len(self.rho.shape) ==1
except :
raise RuntimeError, "Argument rho mismatch"
assert self.eps.shape[0] == self.rho.shape[0], "Dimensions of eps and rho do not match"
#-------------------------------------------------------------
def __reduce__(self) :
return self.__class__, (self.eps,self.rho, self.name)
def __reduce_to_dict__(self) :
return {'epsilon' : self.eps, 'rho': self.rho, 'name' : self.name}
@classmethod
def __factory_from_dict__(cls,D) :
return cls(D['epsilon'],D['rho'], D['name'])
def __repr__(self) :
return """
DOS object :
"""%self.__dict__
def _plot_(self, Options) :
return [ {'type' : "XY", 'label' : self.name, 'xlabel' :r'$\epsilon$', 'ylabel' : r'%s$(\epsilon)$'%self.name, 'xdata' : self.eps,'ydata' : self.rho } ]
def density(self,mu=0):
"""Calculates the density of free fermions for the given DOS for chemical potential mu."""
dens = 0.0
a = [ (e>mu) for e in self.eps ]
try:
ind = a.index(True)
except:
ind = self.eps.shape[0]
de = self.eps[1]-self.eps[0]
#for e,r in itertools.izip(self.eps[0:ind],self.rho[0:ind]):
# dens += r
dens = (sum(self.rho[0:ind]) - self.rho[0]/2.0 - self.rho[ind-1]/2.0) * de
#dens2 = dens + (self.rho[ind-1]/2.0 + self.rho[ind]/2.0) * de
if (ind<self.eps.shape[0]): dens += (mu-self.eps[ind-1]) * (self.rho[ind-1] + self.rho[ind])/2.0
return dens
##########################################################################
def dos_from_file(Filename, name = '', single_orbital = None):
"""
Read the DOS from a file
:param Filename: a string : name of the file
:param name: name of the DOS
:param single_orbital: can be None or an integer.
:rtype:
* if single_orbital== None, returns a tuple of DOS (even if there is one dos !).
* If single_orbital==i, return only ONE DOS corresponding to ith orbital (starting at 1).
Format of the file :
* N_orbitals +1 columns,
* the first column is the value of epsilon
* the N_orbitals other columns are the values of the dos for various orbitals
"""
f = open(Filename); s=''
while not(s.strip()) :
s= f.readline()
assert s, "File is empty !"
N_Orbitals = len (s.split()) - 1
assert N_Orbitals >0, "File : wrong format"
# not very safe : fromfile routine can crashes if given non numerics
r = numpy.fromfile(Filename,sep=' ')
l,div = r.shape[0], N_Orbitals +1
assert l%(div)==0,"File does not contains N*%d numbers !"%(div)
r.shape = l//(div) , div # reshape the array
eps = r[:,0]
if single_orbital :
assert single_orbital>0 and single_orbital <= N_Orbitals, " single_orbital "
return DOS (r[:,0] ,r[:,single_orbital], name)
else :
return [ DOS (r[:,0] ,r[:,i +1 ], name) for i in range (N_Orbitals)]
##########################################################################
class DOSFromFunction(DOS):
"""
* A DOS class, but constructed from a function.
* The number of points can be variable and self-adjusted in the Hilbert transform to adapt precision.
"""
def __init__(self, function, x_min, x_max, n_pts=100, name=''):
"""
:param function: * a function :math:`\\epsilon \\rightarrow \\rho(\\epsilon)`
* The result type can be anything from which a 1d-array can be constructed by numpy
:param x_min,x_max: Bound of the mesh (domain of the function).
:param n_pts: Number of points in the mesh.
:param name: Name of the DOS.
"""
assert callable(function), "function is not callable"
self.function,self.x_min,self.x_max = function,x_min,x_max
try :
e = function(0.001)
len(numpy.array(e).shape) ==1
except :
raise RuntimeError , "Value of the function must be a 1d-array"
self.__f(n_pts) # compute arrays
DOS.__init__(self,self.eps,self.rho,name)
#-------------------------------------------------------------
def __reduce__(self) :
return self.__class__, (self.function,self.x_min, self.x_max, len(self.eps), self.name)
#-------------------------------------------------------------
def __f(self,N) :
r = (self.x_max - self.x_min)/float(N-1)
self.eps = numpy.array( [self.x_min + r* i for i in range(N) ] )
self.rho = numpy.array( [self.function(e) for e in self.eps])
#-----------------------------------------------------
# Register the class for HDFArchive
#-----------------------------------------------------
from pytriqs.archive.hdf_archive_schemes import register_class
register_class (DOS)