Classes
FFTRecon (data, ran, Nmesh[, bias, f, los, …]) 
FFT based Lagrangian reconstruction algorithm in a periodic box. 
nbodykit.algorithms.fftrecon.
FFTRecon
(data, ran, Nmesh, bias=1.0, f=0.0, los=[0, 0, 1], R=20, position='Position', revert_rsd_random=False, scheme='LGS', BoxSize=None)[source]¶FFT based Lagrangian reconstruction algorithm in a periodic box.
References
Eisenstein et al, 2007 http://adsabs.harvard.edu/abs/2007ApJ…664..675E Section 3, paragraph starting with ‘Restoring in full the …’
We follow a cleaner description in Schmitfull et al 2015,
Table I, and text below. Schemes are LGS, LF2 and LRR.
A slight difference against the paper is that Redshift distortion and bias are corrected in the linear order. The Random shifting followed Martin White’s suggestion to exclude the RSD by default. (with default revert_rsd_random=False.)
Parameters: 


Attributes: 
Methods
apply (func[, kind, mode]) 
Return a view of the mesh, with actions updated to apply the specified function, either in Fourier space or configuration space, based on mode 
compute ([mode, Nmesh]) 
Compute / Fetch the mesh object into memory as a RealField or ComplexField object. 
preview ([axes, Nmesh, root]) 
Gather the mesh into as a numpy array, with (reduced) resolution. 
save (output[, dataset, mode]) 
Save the mesh as a BigFileMesh on disk, either in real or complex space. 
to_complex_field ([out]) 
Convert the mesh source to the Fourierspace field, returning a pmesh.pm.ComplexField object. 
to_field ([mode, out]) 
Return the mesh as a pmesh Field object, either in Fourier space or configuration space, based on mode . 
to_real_field () 
Convert the mesh source to the configurationspace field, returning a pmesh.pm.RealField object. 
view () 
Return a “view” of the MeshSource, in the spirit of numpy’s ndarray view. 
paint  
run  
work_with 
__finalize__
(other)¶Finalize the creation of a MeshSource object by copying over attributes from a second MeshSource.
Parameters:  other (MeshSource) – the second MeshSource to copy over attributes from 

__len__
()¶Length of a mesh source is zero
actions
¶A list of actions to apply to the density field when interpolating to the mesh.
This stores tuples of (mode, func, kind)
; see apply()
for more details.
apply
(func, kind='wavenumber', mode='complex')¶Return a view of the mesh, with actions
updated to
apply the specified function, either in Fourier space or
configuration space, based on mode
Parameters: 


Returns:  a view of the mesh object with the 
Return type: 
attrs
¶A dictionary storing relevant metadata about the CatalogSource.
compute
(mode='real', Nmesh=None)¶Compute / Fetch the mesh object into memory as a RealField or ComplexField object.
preview
(axes=None, Nmesh=None, root=0)¶Gather the mesh into as a numpy array, with (reduced) resolution. The result is broadcast to all ranks, so this uses \(\mathrm{Nmesh}^3\) per rank.
Parameters:  

Returns:  out – An numpy array holding the real density field. 
Return type:  array_like 
save
(output, dataset='Field', mode='real')¶Save the mesh as a BigFileMesh
on disk, either in real or complex space.
Parameters: 

to_complex_field
(out=None)¶Convert the mesh source to the Fourierspace field,
returning a pmesh.pm.ComplexField
object.
Not implemented in the base class, unless object is a view.
to_field
(mode='real', out=None)¶Return the mesh as a pmesh
Field object, either in Fourier
space or configuration space, based on mode
.
This will call to_real_field()
or to_complex_field()
based on mode
.
Parameters:  mode ('real' or 'complex') – the return type of the field 

Returns:  either a RealField of ComplexField, storing the value of the field on the mesh 
Return type:  RealField , ComplexField 
to_real_field
()[source]¶Convert the mesh source to the configurationspace field,
returning a pmesh.pm.RealField
object.
Not implemented in the base class, unless object is a view.
view
()¶Return a “view” of the MeshSource, in the spirit of numpy’s ndarray view.
This returns a new MeshSource whose memory is owned by self
.
Note that for CatalogMesh objects, this is overidden by the
CatalogSource.view
function.