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authorAaron LI <aaronly.me@outlook.com>2017-01-05 13:19:08 +0800
committerAaron LI <aly@aaronly.me>2017-06-01 16:33:37 +0800
commit9d8b8c13dcd1767c818e3f49c99206e159a6847c (patch)
tree2f1e3800adf1094374323e9ecd408e30fe974f96 /fg21sim/extragalactic/clusters/mergertree.py
parent86e1d360087a5f72081b18b2630ffc098af39e95 (diff)
downloadfg21sim-9d8b8c13dcd1767c818e3f49c99206e159a6847c.tar.bz2
Add clusters/mergertree.py
The merger tree is a binary tree that represents the merging (or formation) history of a cluster.
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diff --git a/fg21sim/extragalactic/clusters/mergertree.py b/fg21sim/extragalactic/clusters/mergertree.py
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+# Copyright (c) 2017 Weitian LI <liweitianux@live.com>
+# MIT license
+
+"""
+Merger tree that represents the merging history of a cluster using
+the binary tree data structure.
+"""
+
+import os
+import pickle
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+class MergerTree:
+ """
+ A binary tree that represents the cluster merging history.
+
+ Description
+ -----------
+ Merged (M0, z0, age0)
+ ~~~~~~~~~~~~~~~~~~~~~
+ / \
+ Main (M1, z1, age1) Sub (M2, z2, age2)
+ ~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
+ * "Merged" is the merged cluster from "Main" and "Sub" at redshift
+ z1 (=z2) or cosmic time age1 (=age2).
+ M0 = M1 + M2, M1 > M2
+ * If "Sub" is missing, then this is an accretion event (not a merger).
+
+ Parameters
+ ----------
+ data : dict
+ Data (e.g., mass, redshift, age) associated with this tree node.
+ main, sub : `~MergerTree`
+ Links to the main and sub (optional) clusters between which the
+ merger happens.
+ The ``sub`` cluster may be missing, which is regarded as an
+ accretion event rather than a merger.
+ merged : `~MergerTree`
+ Reverse link to the merged cluster. Therefore, it is able to refer
+ to the ``sub`` cluster from the ``main`` cluster, and vice versa.
+ """
+ def __init__(self, data, main=None, sub=None, merged=None):
+ self.data = data
+ self.main = main
+ self.sub = sub
+ self.merged = merged
+
+
+def save_mtree(mtree, outfile, clobber=False):
+ """
+ Pickle the merger tree data and save to file.
+ """
+ if os.path.exists(outfile):
+ if clobber:
+ os.remove(outfile)
+ logger.warning("Removed existing file: {0}".format(outfile))
+ else:
+ raise OSError("Output file already exists: {0}".format(outfile))
+ pickle.dump(mtree, open(outfile, "wb"))
+ logger.info("Saved merger tree to file: {0}".format(outfile))
+
+
+def read_mtree(infile):
+ mtree = pickle.load(open(infile, "wb"))
+ logger.info("Loaded merger tree from file: {0}".format(infile))
+ return mtree
+
+
+def plot_mtree(mtree):
+ """
+ Plot the cluster merger tree.
+ """
+ raise NotImplementedError