Replacement manager

.gitignore

@@ -66,6 +66,9 @@ pip-wheel-metadata
 # VS Code
 .vscode
 
+# Emacs - projectile
+TAGS
+
 # default pytest cache directory
 */.pytest_cache
 .pytest_cache/

docs/Makefile

@@ -0,0 +1,177 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+PAPER         =
+BUILDDIR      = build
+
+# User-friendly check for sphinx-build
+ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
+$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
+endif
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
+
+.PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest gettext
+
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  dirhtml    to make HTML files named index.html in directories"
+	@echo "  singlehtml to make a single large HTML file"
+	@echo "  pickle     to make pickle files"
+	@echo "  json       to make JSON files"
+	@echo "  htmlhelp   to make HTML files and a HTML help project"
+	@echo "  qthelp     to make HTML files and a qthelp project"
+	@echo "  devhelp    to make HTML files and a Devhelp project"
+	@echo "  epub       to make an epub"
+	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  latexpdfja to make LaTeX files and run them through platex/dvipdfmx"
+	@echo "  text       to make text files"
+	@echo "  man        to make manual pages"
+	@echo "  texinfo    to make Texinfo files"
+	@echo "  info       to make Texinfo files and run them through makeinfo"
+	@echo "  gettext    to make PO message catalogs"
+	@echo "  changes    to make an overview of all changed/added/deprecated items"
+	@echo "  xml        to make Docutils-native XML files"
+	@echo "  pseudoxml  to make pseudoxml-XML files for display purposes"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
+
+clean:
+	rm -rf $(BUILDDIR)/*
+
+html:
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+singlehtml:
+	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
+	@echo
+	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
+
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/einsteinpy.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/einsteinpy.qhc"
+
+devhelp:
+	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
+	@echo
+	@echo "Build finished."
+	@echo "To view the help file:"
+	@echo "# mkdir -p $$HOME/.local/share/devhelp/einsteinpy"
+	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/einsteinpy"
+	@echo "# devhelp"
+
+epub:
+	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
+	@echo
+	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
+
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make' in that directory to run these through (pdf)latex" \
+	      "(use \`make latexpdf' here to do that automatically)."
+
+latexpdf:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through pdflatex..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+latexpdfja:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through platex and dvipdfmx..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf-ja
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+text:
+	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
+	@echo
+	@echo "Build finished. The text files are in $(BUILDDIR)/text."
+
+man:
+	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
+	@echo
+	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
+
+texinfo:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo
+	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
+	@echo "Run \`make' in that directory to run these through makeinfo" \
+	      "(use \`make info' here to do that automatically)."
+
+info:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo "Running Texinfo files through makeinfo..."
+	make -C $(BUILDDIR)/texinfo info
+	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
+
+gettext:
+	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
+	@echo
+	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
+
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."
+
+xml:
+	$(SPHINXBUILD) -b xml $(ALLSPHINXOPTS) $(BUILDDIR)/xml
+	@echo
+	@echo "Build finished. The XML files are in $(BUILDDIR)/xml."
+
+pseudoxml:
+	$(SPHINXBUILD) -b pseudoxml $(ALLSPHINXOPTS) $(BUILDDIR)/pseudoxml
+	@echo
+	@echo "Build finished. The pseudo-XML files are in $(BUILDDIR)/pseudoxml."

src/riccipy/__init__.py

@@ -1,5 +1,4 @@
 """
-=======
 RicciPy
 =======
 

src/riccipy/metric.py

@@ -4,7 +4,7 @@
 from sympy.tensor.tensor import TensorIndexType
 
 from .partial import PartialDerivative
-from .tensor import AbstractTensor, ReplacementManager, Tensor, expand_tensor, indices
+from .tensor import AbstractTensor, Tensor, expand_tensor, indices
 
 
 class Metric(AbstractTensor, TensorIndexType):
@@ -67,7 +67,7 @@ def __new__(cls, symbol, coords, matrix, **kwargs):
         obj = AbstractTensor.__new__(cls, obj, array)
         obj.metric = Tensor(obj.name, array, obj, covar=(-1, -1))
         obj.coords = tuple(coords)
-        ReplacementManager[obj] = array
+        obj._repl[obj] = array
         return obj
 
     def __getattr__(self, attr):

src/riccipy/tensor.py

@@ -1,6 +1,6 @@
 from collections import defaultdict
 
-from sympy import Array, simplify, symbols
+from sympy import Array, preorder_traversal, simplify, symbols
 from sympy.core.compatibility import string_types
 from sympy.tensor.array import permutedims, tensorcontraction, tensorproduct
 from sympy.tensor.tensor import (
@@ -14,52 +14,28 @@
 )
 
 
-class _ReplacementManager(dict):
-    """
-    Dictionary for keeping track of the arrays for the symbolically defined
-    tensors.
-
-    Array calculations for tensors is done in Sympy with the
-    ~TensExpr.replace_with_arrays method which takes a dictionary as an argument.
-    Thus, this class provides a convenient interface for bridging between
-    EinsteinPy's interface and Sympy's.
-
-    """
-
-    def get_key(self, tensor):
+class Repl(dict):
+    def getkey(self, tensor):
         item = tensor if (tensor.is_TensorHead or tensor.is_Metric) else tensor.args[0]
         for key in self.keys():
             if (key == item) or (key.args[0] == item):
                 return key
         return None
 
-    def get_value(self, tensor):
-        key = self.get_key(tensor)
-        if key is None:
-            raise KeyError(str(tensor))
-        return self[key]
+    def haskey(self, tensor):
+        key = self.getkey(tensor)
+        return True if key is not None else False
 
-    def remove(self, tensor):
-        key = self.get_key(tensor)
+    def setitem(self, tensor, array):
+        key = self.getkey(tensor)
         if key is not None:
-            self.pop(key)
-
-    def replace(self, tensor, array):
-        key = self.get_key(tensor)
-        if key is None:
-            raise KeyError(str(tensor))
-        self.update({key: array})
-
-    def has(self, tensor):
-        key = self.get_key(tensor)
-        return True if key is not None else False
+            return super().__setitem__(key, array)
+        raise KeyError(str(tensor))
 
     def __setitem__(self, tensor, array):
-        if not self.has(tensor):
-            self.update({tensor: array})
-
-
-ReplacementManager = _ReplacementManager()
+        if self.haskey(tensor):
+            return self.setitem(tensor, array)
+        return super().__setitem__(tensor, array)
 
 
 class AbstractTensor(object):
@@ -77,6 +53,7 @@ class AbstractTensor(object):
 
     def __new__(cls, obj, matrix):
         obj._array = matrix
+        obj._repl = Repl()
         return obj
 
     def as_matrix(self):
@@ -203,7 +180,7 @@ def __new__(cls, symbol, matrix, metric, **kwargs):
         count = defaultdict(int)  # type: dict
 
         def dummy_fmt_gen(idxtype):
-            # generate a generic index for the entry in ReplacementManager.
+            # generate a generic index for the entry in replacement dictionary.
             fmt = idxtype.dummy_fmt
             n = count[idxtype]
             count[idxtype] += 1
@@ -219,7 +196,7 @@ def dummy_fmt_gen(idxtype):
         idxs = [
             idx if covar[pos] > 0 else -idx for pos, idx in enumerate(idx_generator)
         ]
-        ReplacementManager[obj(*idxs)] = array
+        obj._repl[obj(*idxs)] = array
         return obj
 
     def __repr__(self):
@@ -271,12 +248,12 @@ def covariance_transform(self, *indices):
     def simplify(self):
         """
         Replace the stored array associated with this tensor with a simplified
-        version. This method also replaces the entry in ReplacementManager.
+        version. This method also replaces the entry in the replacement dictionary.
 
         """
         array = simplify(self.as_array())
         self._array = array
-        ReplacementManager.replace(self, array)
+        self._repl.setitem(self, array)
         return array
 
 
@@ -304,9 +281,17 @@ def expand_tensor(expr, idxs=None):
         Indices that encode the covariance and contravariance of the result.
 
     """
+    repl = Repl()
+
+    for arg in preorder_traversal(expr):
+        if isinstance(arg, AbstractTensor):
+            repl.update(arg._repl)
+            for metric in arg.index_types:
+                repl.update(metric._repl)
+
     if idxs is None:
         idxs = TensMul(expr).get_free_indices()
-    return expr.replace_with_arrays(ReplacementManager, idxs)
+    return expr.replace_with_arrays(repl, idxs)
 
 
 def indices(s, metric, is_up=True):

src/riccipy/tests/test_metric.py

@@ -1,8 +1,7 @@
-from sympy import Expr, diag, eye, sin, symbols, tensorproduct, zeros
-
 from riccipy.metric import *
 from riccipy.partial import *
 from riccipy.tensor import *
+from sympy import Expr, diag, eye, sin, symbols, tensorproduct, zeros
 
 
 def _generate_schwarzschild():
@@ -97,9 +96,9 @@ def test_Metric_einstein():
 
 def test_Metric_weyl():
     x, y, z = symbols("x y z", real=True)
-    I = Metric("I", (x, y, z), eye(3))
+    eta = Metric("eta", (x, y, z), eye(3))
     zero_tensor = tensorproduct(zeros(3, 3), zeros(3, 3))
-    assert I.weyl.as_array() == zero_tensor
+    assert eta.weyl.as_array() == zero_tensor
 
     (coords, t, r, th, ph, schw, g, mu, nu) = _generate_schwarzschild()
     rh, si = indices("rho sigma", g)

src/riccipy/tests/test_partial.py

@@ -1,8 +1,7 @@
-from sympy import diag, sin, symbols
-
 from riccipy.metric import *
 from riccipy.partial import *
 from riccipy.tensor import *
+from sympy import diag, sin, symbols
 
 
 def _generate_schwarzschild():

src/riccipy/tests/test_tensor.py

@@ -1,8 +1,7 @@
-from sympy import Array, diag, eye, simplify, sin, symbols
-from sympy.tensor.tensor import TensExpr, TensMul
-
 from riccipy.metric import *
 from riccipy.tensor import *
+from sympy import Array, diag, eye, simplify, sin, symbols
+from sympy.tensor.tensor import TensExpr, TensMul
 
 
 def _generate_simple():
@@ -103,10 +102,6 @@ def test_IndexedTensor():
     assert isinstance(T(mu), IndexedTensor)
 
 
-def test_ReplacementManager():
-    pass
-
-
 def test_expand_tensor():
     (coords, t, r, th, ph, mink, eta, mu, nu) = _generate_minkowski()
     E1, E2, E3, B1, B2, B3 = symbols("E_1:4 B_1:4", real=True)