yt.utilities.lib.cyoctree module

CyOctree building, loading and refining routines

class yt.utilities.lib.cyoctree.CyOctree

Bases: object

This a class to store the underlying octree and particle data that can be interacted with from both Cython and Python

bound_particles

The particle selection may select SPH particles with smoothing lengths which is in the octree domains. However, if the particle center is NOT in the octree, they are not included.

So the number of particles passed to the tree may not be equal to the number of particles which are bound by the tree.

interpolate_sph_cells(buff, buff_den, posx, posy, posz, pmass, pdens, hsml, field, kernel_name='cubic', use_normalization=0)

We loop through every particle in the simulation and begin to deposit the particle properties onto all of the leaves that it intersects

Parameters:

  • buff (memoryview) – The array which we are depositing the field onto, it has the length of the number of leaves.

  • buff_den (memoryview) – The array we deposit just mass onto to allow normalization

  • pos<> (memoryview) – The x, y, and z coordinates of all the partciles

  • pmass (memoryview) – The mass of the particles

  • pdens (memoryview) – The density of the particles

  • hsml (memoryview) – The smoothing lengths of the particles

  • field (memoryview) – The field we are depositing for each particle

  • kernel_name (str, default: "cubic") – Choice of kernel for SPH deposition

  • use_normalization (int, default: 0) – Do we want a normalized sph field? If so, fill the buff_den.

node_depth

The depth for each node in the tree. The root node is defined as a depth of 0.

node_positions

The centre of every node within the octree

node_refined

An array of length num_nodes which contains either True / False for whether each cell has refined or not. E.g False for a leaf, True for a node

node_sizes

The size of each node in the x, y and z directions. We calculate this on the fly. As we know the size of the whole tree and the depth of each node

num_nodes

The total number of nodes after tree construction