Require SageMath to be installed

.github/workflows/test.yml

@@ -34,6 +34,25 @@ jobs:
           - optionals: "sage,sage_flatsurf,pyeantic,pyintervalxt,surface_dynamics,flipper"
             sagelib: "10.0"
             python: "3.10.5"
+          # Test optional dependencies in isolation
+          - optionals: "sage"
+            sagelib: "10.0"
+            python: "3.10.5"
+          - optionals: "sage,sage_flatsurf"
+            sagelib: "10.0"
+            python: "3.10.5"
+          - optionals: "sage,pyeantic"
+            sagelib: "10.0"
+            python: "3.10.5"
+          - optionals: "sage,pyintervalxt"
+            sagelib: "10.0"
+            python: "3.10.5"
+          - optionals: "sage,surface_dynamics"
+            sagelib: "10.0"
+            python: "3.10.5"
+          - optionals: "sage,flipper"
+            sagelib: "10.0"
+            python: "3.10.5"
     steps:
       - uses: actions/checkout@v2
         with: { submodules: recursive }
@@ -42,8 +61,10 @@ jobs:
       - name: Install dependencies
         shell: bash -l {0}
         run: |
-          mamba install -n test sagelib=${{ matrix.sagelib }}
-          echo "sagelib ==${{ matrix.sagelib }}" >> $CONDA_PREFIX/conda-meta/pinned
+          if (echo "${{ matrix.optionals }}" | grep sage); then
+            mamba install -n test sagelib=${{ matrix.sagelib }}
+            echo "sagelib ==${{ matrix.sagelib }}" >> $CONDA_PREFIX/conda-meta/pinned
+          fi
 
           while read; do
             optional=$(echo "$REPLY" | grep -o '# optional: [^ ]*' | awk '{ print $3; }') || true

README.rst

@@ -1,23 +1,16 @@
 Veerer
 ======
 
-Veerer is a Python package to deal with veering triangulations of surfaces and
-their associated flat structures. It can in particular be used to provide
-representatives of pseudo-Anosov mapping classes of surfaces. The theoretical
-background is based on ideas of I. Agol and F. Guéritaud, and is developed in:
+Veerer is a package for `SageMath <https://www.sagemath.org>`_ to deal with
+veering triangulations of surfaces and their associated flat structures. It can
+in particular be used to provide representatives of pseudo-Anosov mapping
+classes of surfaces. The theoretical background is based on ideas of I. Agol
+and F. Guéritaud, and is developed in:
 
 M. Bell, V. Delecroix, V. Gadre, R. Gutiérrez-Romo, S. Schleimer,
 "Coding Teichmüller flow using veering triangulations",
 `arXiv:1909.00890 <https://arxiv.org/abs/1909.00890>`_.
 
-To install this package you only need Python but additional features are
-available if this package is used inside `SageMath
-<https://www.sagemath.org/>`_.
-
-Computations involving polytopes are only available if the Python package
-`pplpy <https://github.com/sagemath/pplpy>`_ is available. It is installed
-by default with SageMath, version 8.7 or above.
-
 Example
 -------
 

environment.yml

@@ -6,6 +6,7 @@ name: veerer-build
 channels:
   - conda-forge
 dependencies:
+  - cython
   - pytest
   - pytest-xdist
   - ipywidgets

veerer/automaton.py

@@ -187,8 +187,6 @@ def to_graph(self, directed=True, multiedges=True, loops=True):
             sage: A.to_graph(directed=False, multiedges=False, loops=True)
             Looped graph on 86 vertices
         """
-        require_package('sage', 'to_graph')
-
         if directed:
             from sage.graphs.digraph import DiGraph
             G = DiGraph(loops=loops, multiedges=multiedges)

veerer/env.py

@@ -28,36 +28,10 @@
 
 CHECK = False
 
-try:
-    import sage.all
-    import sage
-except ImportError:
-    sage = None
-    import random
-    op_LT = 0
-    op_LE = 1
-    op_EQ = 2
-    op_NE = 3
-    op_GT = 4
-    op_GE = 5
-    def rich_to_bool(op, c):
-        if op == op_EQ:
-            return c == 0
-        elif op == op_NE:
-            return c != 0
-        elif op == op_LT:
-            return c < 0
-        elif op == op_LE:
-            return c <= 0
-        elif op == op_GE:
-            return c >= 0
-        elif op == op_GT:
-            return c > 0
-        else:
-            raise RuntimeError
-else:
-    import sage.misc.prandom as random
-    from sage.structure.richcmp import op_LT, op_LE, op_EQ, op_NE, op_GT, op_GE, rich_to_bool
+import sage.all
+import sage
+import sage.misc.prandom as random
+from sage.structure.richcmp import op_LT, op_LE, op_EQ, op_NE, op_GT, op_GE, rich_to_bool
 
 
 try:
@@ -90,8 +64,6 @@ def rich_to_bool(op, c):
 error_msg = {
     'curver': 'the function {} can only be called when the package curver is installed.',
 
-    'sage': 'the function {} can only be called when running inside of Sage. See https://www.sagemath.org/',
-
     'surface_dynamics': 'the function {} only works when the package surface_dynamics is installed. See https://pypi.org/project/surface_dynamics/ for instructions.',
 
     'flipper': 'the function {} only works when the package flipper is installed. See https://pypi.org/project/flipper/ for instructions',
@@ -103,7 +75,6 @@ def rich_to_bool(op, c):
 
 missing_mods = {
     'curver': curver is None,
-    'sage': sage is None,
     'flipper': flipper is None,
     'ppl': ppl is None,
     'surface_dynamics': surface_dynamics is None,

veerer/flip_sequence.py

@@ -196,7 +196,6 @@ def copy(self):
         return F
 
     def matrix(self, twist=True):
-        require_package('sage', 'matrix')
         from sage.rings.all import ZZ
         from sage.matrix.special import identity_matrix
         m = identity_matrix(ZZ, self._start.num_edges())
@@ -321,7 +320,6 @@ def inverse(self):
         return F
 
     def matrix_inverse(self, twist=True):
-        require_package('sage', 'matrix')
         from sage.rings.all import ZZ
         from sage.matrix.special import identity_matrix
         m = identity_matrix(ZZ, self._start.num_edges())
@@ -520,7 +518,6 @@ def self_similar_widths_and_heights(self):
             sage: f.start().colouring_from_xy(x, y)[:9] == f.end_colouring()
             True
         """
-        require_package('sage', 'self_similar_surface')
         from sage.rings.qqbar import AA
 
         wm = self.inverse().matrix() # matrix: widths_end -> widths_start

veerer/polyhedron/linear_expression.py

@@ -26,8 +26,6 @@
 
 from ..env import require_package, sage, ppl
 
-require_package('sage', 'linear_expression')
-
 from sage.categories.modules import Modules
 
 from sage.structure.unique_representation import UniqueRepresentation
@@ -563,7 +561,6 @@ def cone(self, backend='sage'):
             from .cone import Cone_ppl
             return Cone_ppl(QQ, ppl.C_Polyhedron(self.ppl()))
         elif backend == 'sage':
-            require_package('sage', 'cone')
             from .cone import Cone_sage
             ieqs, eqns = self.ieqs_eqns()
             return Cone_sage._new(ieqs, eqns)

veerer/triangulation.py

@@ -921,7 +921,6 @@ def homology_matrix(self):
             [ 1  0  1  0  1  1  0]
             [ 0  1  0  0 -1  0  0]
         """
-        require_package('sage', 'homology_matrix')
         from sage.matrix.constructor import matrix
         from sage.rings.integer_ring import ZZ
 

veerer/veering_quadrangulation.py

@@ -189,7 +189,7 @@ def stratum_component(self):
             H_2(2)^hyp
             sage: q = VeeringQuadrangulation("(0,1,2,3,4)", "(0)(1,2)(3,4)")
             sage: component = q.stratum_component() # optional - surface_dynamics  # random output due to deprecation warnings from surface dynamics
-            sage: component
+            sage: component  # optional - surface_dynamics
             H_3(4)^odd
         """
         return self.to_origami().stratum_component()

veerer/veering_triangulation.py

@@ -306,8 +306,6 @@ def as_linear_family(self, mutable=False):
             sage: vt.as_linear_family()
             VeeringTriangulationLinearFamily("(0,1,2)(~2,~0,~1)", "RRB", [(1, 0, -1), (0, 1, 1)])
         """
-        require_package('sage', 'as_linear_family')
-
         from .linear_family import VeeringTriangulationLinearFamily
         P = self.train_track_linear_space()
         return VeeringTriangulationLinearFamily(self, self.train_track_linear_space().lines(), mutable=mutable)
@@ -3012,8 +3010,6 @@ def _complexify_generators(self, Gx):
             sage: T._set_switch_conditions(T._tt_check, Gy.row(0), HORIZONTAL)
             sage: T._set_switch_conditions(T._tt_check, Gy.row(1), HORIZONTAL)
         """
-        require_package('sage', '_complexify_generators')
-
         ne = self.num_edges()
         ep = self._ep
         if Gx.ncols() != ne:
@@ -3054,8 +3050,6 @@ def _complexify_equations(self, Lx):
             sage: V2 = V.subspace(Gy.right_kernel_matrix())
             sage: assert V1 == V2
         """
-        require_package('sage', '_complexify_equations')
-
         ne = self.num_edges()
         ep = self._ep
         if Lx.ncols() != ne:
@@ -3074,8 +3068,6 @@ def _flat_structure_from_train_track_lengths(self, VH, VV, base_ring=None, mutab
         Return a flat structure from two vectors ``VH`` and ``VV``
         satisfying the train track equations.
         """
-        require_package('sage', '_flat_structure_from_train_track_lengths')
-
         from sage.modules.free_module import VectorSpace
 
         if base_ring is None:
@@ -3180,8 +3172,6 @@ def flat_structure_min(self, allow_degenerations=False):
             sage: F.to_veering_triangulation()                    # optional - surface_dynamics
             VeeringTriangulation("(0,18,~17)(1,20,~19)...(19,~18,~0)", "RRRRRRRRBBBBBBBBBGBBBBBP")
         """
-        require_package('sage', 'flat_structure_min')
-
         VH = self.train_track_min_solution(HORIZONTAL, allow_degenerations=allow_degenerations)
         VV = self.train_track_min_solution(VERTICAL, allow_degenerations=allow_degenerations)