nbodykit.source.mesh.linear¶

Classes

class nbodykit.source.mesh.linear.LinearMesh(Plin, BoxSize, Nmesh, seed=None, unitary_amplitude=False, inverted_phase=False, remove_variance=None, comm=None)[source]¶

A MeshSource object that generates a RealField density mesh from a linear power spectrum function \(P(k)\).

Parameters:

Plin (callable) – the callable linear power spectrum function, which takes the wavenumber as its single argument BoxSize (float, 3-vector of floats) – the size of the box to generate the grid on Nmesh (int, 3-vector of int) – the number of the mesh cells per side seed (int, optional) – the global random seed, used to set the seeds across all ranks remove_variance (bool, optional) – :deprecated:`use unitary_amplitude instead` True to remove variance from the complex field by fixing the amplitude to \(P(k)\) and only the phase is random. unitary_amplitude (bool, optional) – True to remove variance from the complex field by fixing the amplitude to \(P(k)\) and only the phase is random. inverted_phase (bool, optional) – True to invert phase of the complex field by fixing the amplitude to \(P(k)\) and only the phase is random. comm (MPI communicator) – the MPI communicator

Attributes

actions	A list of actions to apply to the density field when interpolating to the mesh.
attrs	A dictionary storing relevant meta-data about the CatalogSource.

Methods

apply(func[, kind, mode])	Return a view of the mesh, with actions updated to
paint([mode, Nmesh])	Paint the density on the mesh and apply any transformation functions specified in actions.
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()	Return a ComplexField, generating from the linear power spectrum.
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([out, normalize])	Convert the mesh source to the configuration-space field, returning a pmesh.pm.RealField object.
view()	Return a “view” of the MeshSource, in the spirit of numpy’s ndarray view.

to_complex_field()[source]¶

Return a ComplexField, generating from the linear power spectrum.

Note

The density field is normalized to \(1+\delta\) such that the mean of the return field in real space is unity.

Returns:	an array-like object holding the generated linear density field in Fourier space
Return type:	pmesh.pm.ComplexField