Source code for yt.analysis_modules.level_sets.clump_handling

Clump finding helper classes


# Copyright (c) 2013, yt Development Team.
# Distributed under the terms of the Modified BSD License.
# The full license is in the file COPYING.txt, distributed with this software.

import numpy as np
import uuid

from yt.fields.derived_field import \
from yt.frontends.ytdata.utilities import \
from yt.funcs import \
    deprecate, \
    get_output_filename, \
    iterable, \
from yt.extern.six import \
from yt.utilities.tree_container import \

from .clump_info_items import \
from .clump_validators import \
from .contour_finder import \

[docs]def add_contour_field(ds, contour_key): def _contours(field, data): fd = data.get_field_parameter("contour_slices_%s" % contour_key) vals = data["index", "ones"] * -1 if fd is None or fd == 0.0: return vals for sl, v in fd.get(, []): vals[sl] = v return vals ds.add_field(("index", "contours_%s" % contour_key), function=_contours, validators=[ValidateSpatial(0)], take_log=False, display_field=False, sampling_type='cell', units='')
[docs]class Clump(TreeContainer): children = None def __init__(self, data, field, parent=None, clump_info=None, validators=None, base=None, contour_key=None, contour_id=None): = data self.field = field self.parent = parent self.quantities = data.quantities self.min_val =[field].min() self.max_val =[field].max() = {} # is this the parent clump? if base is None: base = self self.total_clumps = 0 if clump_info is None: self.set_default_clump_info() else: self.clump_info = clump_info self.base = base self.clump_id = self.base.total_clumps self.base.total_clumps += 1 self.contour_key = contour_key self.contour_id = contour_id if parent is not None: = if parent is not None: = if validators is None: validators = [] self.validators = validators # Return value of validity function. self.valid = None
[docs] def add_validator(self, validator, *args, **kwargs): """ Add a validating function to determine whether the clump should be kept. """ callback = clump_validator_registry.find(validator, *args, **kwargs) self.validators.append(callback) if self.children is None: return for child in self.children: child.add_validator(validator)
[docs] def add_info_item(self, info_item, *args, **kwargs): "Adds an entry to clump_info list and tells children to do the same." callback = clump_info_registry.find(info_item, *args, **kwargs) self.clump_info.append(callback) if self.children is None: return for child in self.children: child.add_info_item(info_item)
[docs] def set_default_clump_info(self): "Defines default entries in the clump_info array." # add_info_item is recursive so this function does not need to be. self.clump_info = [] self.add_info_item("total_cells") self.add_info_item("cell_mass") if any("jeans" in f for f in self.add_info_item("mass_weighted_jeans_mass") self.add_info_item("volume_weighted_jeans_mass") self.add_info_item("max_grid_level") if any("number_density" in f for f in self.add_info_item("min_number_density") self.add_info_item("max_number_density")
[docs] def clear_clump_info(self): """ Clears the clump_info array and passes the instruction to its children. """ self.clump_info = [] if self.children is None: return for child in self.children: child.clear_clump_info()
[docs] def write_info(self, level, f_ptr): "Writes information for clump using the list of items in clump_info." for item in self.base.clump_info: value = item(self) f_ptr.write("%s%s\n" % ('\t'*level, value))
[docs] def find_children(self, min_val, max_val = None): if self.children is not None:"Wiping out existing children clumps: %d.", len(self.children)) self.children = [] if max_val is None: max_val = self.max_val nj, cids = identify_contours(, self.field, min_val, max_val) # Here, cids is the set of slices and values, keyed by the # parent_grid_id, that defines the contours. So we can figure out all # the unique values of the contours by examining the list here. unique_contours = set([]) for sl_list in cids.values(): for sl, ff in sl_list: unique_contours.update(np.unique(ff)) contour_key = uuid.uuid4().hex base_object = getattr(, 'base_object', add_contour_field(base_object.ds, contour_key) for cid in sorted(unique_contours): if cid == -1: continue new_clump = base_object.cut_region( ["obj['contours_%s'] == %s" % (contour_key, cid)], {('contour_slices_%s' % contour_key): cids}) if new_clump["ones"].size == 0: # This is to skip possibly duplicate clumps. # Using "ones" here will speed things up. continue self.children.append(Clump(new_clump, self.field, parent=self, validators=self.validators, base=self.base, contour_key=contour_key, contour_id=cid))
def __iter__(self): yield self if self.children is None: return for child in self.children: for a_node in child: yield a_node
[docs] def save_as_dataset(self, filename=None, fields=None): r"""Export clump tree to a reloadable yt dataset. This function will take a clump object and output a dataset containing the fields given in the ``fields`` list and all info items. The resulting dataset can be reloaded as a yt dataset. Parameters ---------- filename : str, optional The name of the file to be written. If None, the name will be a combination of the original dataset and the clump index. fields : list of strings or tuples, optional If this is supplied, it is the list of fields to be saved to disk. Returns ------- filename : str The name of the file that has been created. Examples -------- >>> import yt >>> from yt.analysis_modules.level_sets.api import \ ... Clump, find_clumps >>> ds = yt.load("IsolatedGalaxy/galaxy0030/galaxy0030") >>> data_source = ds.disk([0.5, 0.5, 0.5], [0., 0., 1.], ... (8, 'kpc'), (1, 'kpc')) >>> field = ("gas", "density") >>> step = 2.0 >>> c_min = 10**np.floor(np.log10(data_source[field]).min() ) >>> c_max = 10**np.floor(np.log10(data_source[field]).max()+1) >>> master_clump = Clump(data_source, field) >>> master_clump.add_info_item("center_of_mass") >>> master_clump.add_validator("min_cells", 20) >>> find_clumps(master_clump, c_min, c_max, step) >>> fn = master_clump.save_as_dataset(fields=["density", "particle_mass"]) >>> new_ds = yt.load(fn) >>> print (ds.tree["clump", "cell_mass"]) 1296926163.91 Msun >>> print ds.tree["grid", "density"] [ 2.54398434e-26 2.46620353e-26 2.25120154e-26 ..., 1.12879234e-25 1.59561490e-25 1.09824903e-24] g/cm**3 >>> print ds.tree["all", "particle_mass"] [ 4.25472446e+38 4.25472446e+38 4.25472446e+38 ..., 2.04238266e+38 2.04523901e+38 2.04770938e+38] g >>> print ds.tree.children[0]["clump", "cell_mass"] 909636495.312 Msun >>> print ds.leaves[0]["clump", "cell_mass"] 3756566.99809 Msun >>> print ds.leaves[0]["grid", "density"] [ 6.97820274e-24 6.58117370e-24 7.32046082e-24 6.76202430e-24 7.41184837e-24 6.76981480e-24 6.94287213e-24 6.56149658e-24 6.76584569e-24 6.94073710e-24 7.06713082e-24 7.22556526e-24 7.08338898e-24 6.78684331e-24 7.40647040e-24 7.03050456e-24 7.12438678e-24 6.56310217e-24 7.23201662e-24 7.17314333e-24] g/cm**3 """ ds = keyword = "%s_clump_%d" % (str(ds), self.clump_id) filename = get_output_filename(filename, keyword, ".h5") # collect clump info fields clump_info = dict([(, []) for ci in self.base.clump_info]) clump_info.update( dict([(field, []) for field in ["clump_id", "parent_id", "contour_key", "contour_id"]])) for clump in self: clump_info["clump_id"].append(clump.clump_id) if clump.parent is None: parent_id = -1 else: parent_id = clump.parent.clump_id clump_info["parent_id"].append(parent_id) contour_key = clump.contour_key if contour_key is None: contour_key = -1 clump_info["contour_key"].append(contour_key) contour_id = clump.contour_id if contour_id is None: contour_id = -1 clump_info["contour_id"].append(contour_id) for ci in self.base.clump_info: ci(clump) clump_info[].append([][1]) for ci in clump_info: if hasattr(clump_info[ci][0], "units"): clump_info[ci] = ds.arr(clump_info[ci]) else: clump_info[ci] = np.array(clump_info[ci]) ftypes = dict([(ci, "clump") for ci in clump_info]) # collect data fields if fields is not None: contour_fields = \ [("index", "contours_%s" % ckey) for ckey in np.unique(clump_info["contour_key"]) \ if str(ckey) != "-1"] ptypes = [] field_data = {} need_grid_positions = False for f in + contour_fields: field_data[f] = self.base[f] if ds.field_info[f].particle_type: if f[0] not in ptypes: ptypes.append(f[0]) ftypes[f] = f[0] else: need_grid_positions = True ftypes[f] = "grid" if len(ptypes) > 0: for ax in "xyz": for ptype in ptypes: p_field = (ptype, "particle_position_%s" % ax) if p_field in ds.field_info and \ p_field not in field_data: ftypes[p_field] = p_field[0] field_data[p_field] = self.base[p_field] for clump in self: if clump.contour_key is None: continue for ptype in ptypes: cfield = (ptype, "contours_%s" % clump.contour_key) if cfield not in field_data: field_data[cfield] = \ ftypes[cfield] = ptype field_data[cfield][] = \ clump.contour_id if need_grid_positions: for ax in "xyz": g_field = ("index", ax) if g_field in ds.field_info and \ g_field not in field_data: field_data[g_field] = self.base[g_field] ftypes[g_field] = "grid" g_field = ("index", "d" + ax) if g_field in ds.field_info and \ g_field not in field_data: ftypes[g_field] = "grid" field_data[g_field] = self.base[g_field] if self.contour_key is not None: cfilters = {} for field in field_data: if ftypes[field] == "grid": ftype = "index" else: ftype = field[0] cfield = (ftype, "contours_%s" % self.contour_key) if cfield not in cfilters: cfilters[cfield] = field_data[cfield] == self.contour_id field_data[field] = field_data[field][cfilters[cfield]] clump_info.update(field_data) extra_attrs = {"data_type": "yt_clump_tree", "container_type": "yt_clump_tree"} save_as_dataset(ds, filename, clump_info, field_types=ftypes, extra_attrs=extra_attrs) return filename
[docs] def pass_down(self,operation): """ Performs an operation on a clump with an exec and passes the instruction down to clump children. """ # Call if callable, otherwise do an exec. if callable(operation): operation() else: exec(operation) if self.children is None: return for child in self.children: child.pass_down(operation)
def _validate(self): "Apply all user specified validator functions." # Only call functions if not done already. if self.valid is not None: return self.valid self.valid = True for validator in self.validators: self.valid &= validator(self) if not self.valid: break return self.valid def __reduce__(self): return (_reconstruct_clump, (self.parent, self.field, self.min_val, self.max_val, self.valid, self.children,, self.clump_info, self.function)) def __getitem__(self,request): return[request]
def _reconstruct_clump(parent, field, mi, ma, valid, children, data, clump_info, function=None): obj = object.__new__(Clump) if iterable(parent): try: parent = parent[1] except KeyError: parent = parent if children is None: children = [] obj.parent, obj.field, obj.min_val, obj.max_val, \ obj.valid, obj.children, obj.clump_info, obj.function = \ parent, field, mi, ma, valid, children, clump_info, function # Now we override, because the parent/child relationship seems a bit # unreliable in the unpickling for child in children: child.parent = obj = data[1] # Strip out the PF obj.quantities = if obj.parent is None: return (data[0], obj) return obj
[docs]def find_clumps(clump, min_val, max_val, d_clump):"Finding clumps: min: %e, max: %e, step: %f" % (min_val, max_val, d_clump)) if min_val >= max_val: return clump.find_children(min_val) if (len(clump.children) == 1): find_clumps(clump, min_val*d_clump, max_val, d_clump) elif (len(clump.children) > 0): these_children = []"Investigating %d children." % len(clump.children)) for child in clump.children: find_clumps(child, min_val*d_clump, max_val, d_clump) if ((child.children is not None) and (len(child.children) > 0)): these_children.append(child) elif (child._validate()): these_children.append(child) else:"Eliminating invalid, childless clump with " + "%d cells.") % len(["ones"])) if (len(these_children) > 1):"%d of %d children survived." % (len(these_children),len(clump.children))) clump.children = these_children elif (len(these_children) == 1):"%d of %d children survived, linking its " + "children to parent.") % (len(these_children),len(clump.children))) clump.children = these_children[0].children else:"%d of %d children survived, erasing children." % (len(these_children),len(clump.children))) clump.children = []
[docs]def get_lowest_clumps(clump, clump_list=None): "Return a list of all clumps at the bottom of the index." if clump_list is None: clump_list = [] if clump.children is None or len(clump.children) == 0: clump_list.append(clump) if clump.children is not None and len(clump.children) > 0: for child in clump.children: get_lowest_clumps(child, clump_list=clump_list) return clump_list
[docs]def write_clump_index(clump, level, fh): top = False if isinstance(fh, string_types): fh = open(fh, "w") top = True for q in range(level): fh.write("\t") fh.write("Clump at level %d:\n" % level) clump.write_info(level, fh) fh.write("\n") fh.flush() if ((clump.children is not None) and (len(clump.children) > 0)): for child in clump.children: write_clump_index(child, (level+1), fh) if top: fh.close()
[docs]def write_clumps(clump, level, fh): top = False if isinstance(fh, string_types): fh = open(fh, "w") top = True if ((clump.children is None) or (len(clump.children) == 0)): fh.write("%sClump:\n" % ("\t"*level)) clump.write_info(level, fh) fh.write("\n") fh.flush() if ((clump.children is not None) and (len(clump.children) > 0)): for child in clump.children: write_clumps(child, 0, fh) if top: fh.close()