Add # needs in various places

Author: mkoeppe

src/sage/env.py

@@ -373,6 +373,7 @@ def cython_aliases(required_modules=None, optional_modules=None):
 
     EXAMPLES::
 
+        sage: # needs sage.misc.cython (actually just pkgconfig)
         sage: from sage.env import cython_aliases
         sage: cython_aliases()
         {...}

src/sage/features/databases.py

@@ -53,7 +53,7 @@ class DatabaseCremona(StaticFile):
     EXAMPLES::
 
         sage: from sage.features.databases import DatabaseCremona
-        sage: DatabaseCremona('cremona_mini', type='standard').is_present()
+        sage: DatabaseCremona('cremona_mini', type='standard').is_present()             # needs database_cremona_mini_ellcurve
         FeatureTestResult('database_cremona_mini_ellcurve', True)
         sage: DatabaseCremona().is_present()                                    # optional - database_cremona_ellcurve
         FeatureTestResult('database_cremona_ellcurve', True)

src/sage/geometry/hyperbolic_space/hyperbolic_geodesic.py

@@ -1522,8 +1522,9 @@ def perpendicular_bisector(self):  # UHP
 
         EXAMPLES::
 
-            sage: # needs scipy
             sage: UHP = HyperbolicPlane().UHP()
+
+            sage: # needs scipy
             sage: g = UHP.random_geodesic()
             sage: h = g.perpendicular_bisector().complete()
             sage: c = lambda x: x.coordinates()
@@ -1533,10 +1534,9 @@ def perpendicular_bisector(self):  # UHP
         ::
 
             sage: # needs scipy
-            sage: UHP = HyperbolicPlane().UHP()
-            sage: g = UHP.get_geodesic(1+I,2+0.5*I)
+            sage: g = UHP.get_geodesic(1 + I, 2 + 0.5*I)
             sage: h = g.perpendicular_bisector().complete()
-            sage: show(g.plot(color='blue')+h.plot(color='orange'))
+            sage: show(g.plot(color='blue') + h.plot(color='orange'))
 
         .. PLOT::
 

src/sage/groups/matrix_gps/matrix_group.py

@@ -371,6 +371,7 @@ def sign_representation(self, base_ring=None):
             sage: m2*e*e
             2*B['v']
 
+            sage: # needs sage.groups
             sage: W = WeylGroup(["A", 1, 1])
             sage: W.sign_representation()
             Sign representation of

src/sage/interfaces/magma.py

@@ -246,7 +246,8 @@ def extcode_dir(iface=None):
 
     EXAMPLES::
 
-        sage: sage.interfaces.magma.extcode_dir()
+        sage: from sage.interfaces.magma import extcode_dir
+        sage: extcode_dir()
         '...dir_.../data/'
     """
     global EXTCODE_DIR
@@ -2783,6 +2784,7 @@ def __init__(self, verbosity=1, style='magma'):
 
         EXAMPLES::
 
+            sage: # needs sage.libs.singular
             sage: P.<x,y,z> = GF(32003)[]
             sage: I = sage.rings.ideal.Cyclic(P)
             sage: _ = I.groebner_basis('magma',prot='sage') # indirect doctest, optional - magma, not tested
@@ -2792,6 +2794,7 @@ def __init__(self, verbosity=1, style='magma'):
 
             Highest degree reached during computation:  3.
 
+            sage: # needs sage.libs.singular
             sage: P.<x,y,z> = GF(32003)[]
             sage: I = sage.rings.ideal.Cyclic(P)
             sage: _ = I.groebner_basis('magma',prot=True) # indirect doctest, optional - magma, not tested
@@ -2852,6 +2855,7 @@ def write(self, s):
         """
         EXAMPLES::
 
+            sage: # needs sage.libs.singular
             sage: P.<x,y,z> = GF(32003)[]
             sage: I = sage.rings.ideal.Katsura(P)
             sage: _ = I.groebner_basis('magma',prot=True) # indirect doctest, optional - magma
@@ -2988,6 +2992,7 @@ def magma_gb_standard_options(func):
 
     EXAMPLES::
 
+        sage: # needs sage.libs.singular
         sage: P.<a,b,c,d,e> = PolynomialRing(GF(127))
         sage: J = sage.rings.ideal.Cyclic(P).homogenize()
         sage: from sage.misc.sageinspect import sage_getsource

src/sage/manifolds/differentiable/integrated_curve.py

@@ -45,9 +45,9 @@
 
 Plot the geodesic after interpolating the solution ``sol``::
 
-    sage: interp = c.interpolate()
+    sage: interp = c.interpolate()                                                      # needs scipy
 
-    sage: # needs sage.plot
+    sage: # needs scipy sage.plot
     sage: graph = c.plot_integrated()
     sage: p_plot = p.plot(size=30, label_offset=-0.07, fontsize=20)
     sage: v_plot = v.plot(label_offset=0.05, fontsize=20)
@@ -1544,17 +1544,17 @@ def solve_across_charts(self, charts=None, step=None, solution_key=None,
 
         The interpolation is done as usual::
 
-            sage: interp = c.interpolate()
+            sage: interp = c.interpolate()                                              # needs scipy
 
         To plot the result, you must first be sure that the mapping
         encompasses all the chart, which is the case here.
         You must also specify ``across_charts=True`` in order to call
         :meth:`plot_integrated` again on each part.
         Finally, ``color`` can be a list, which will be cycled through::
 
-            sage: fig += c.plot_integrated(mapping=phi, color=["green","red"],          # needs sage.plot
+            sage: fig += c.plot_integrated(mapping=phi, color=["green","red"],          # needs scipy sage.plot
             ....: thickness=3, plot_points=100, across_charts=True)
-            sage: fig                                                                   # needs sage.plot
+            sage: fig                                                                   # needs scipy sage.plot
             Graphics object consisting of 43 graphics primitives
 
         .. PLOT::
@@ -1948,7 +1948,7 @@ def interpolate(self, solution_key=None, method=None,
             ...
             ValueError: no existing key 'my solution' referring to any
              numerical solution
-            sage: interp = c.interpolate(solution_key='sol_T1',
+            sage: interp = c.interpolate(solution_key='sol_T1',                         # needs scipy
             ....:                        method='my method')
             Traceback (most recent call last):
             ...
@@ -3099,6 +3099,7 @@ class IntegratedAutoparallelCurve(IntegratedCurve):
     Plot the resulting curves on the grid of polar coordinates lines on
     `\mathbb{S}^{2}`::
 
+        sage: # needs sage.plot
         sage: graph3D_embedded_curves = Graphics()
         sage: for key in dict_params:
         ....:     graph3D_embedded_curves += c.plot_integrated(interpolation_key='interp-'+key,

src/sage/matrix/matrix2.pyx

@@ -778,15 +778,15 @@ cdef class Matrix(Matrix1):
         A degenerate case::
 
             sage: A = matrix(RDF, 0, 0, [])
-            sage: A.solve_right(vector(RDF,[]))
+            sage: A.solve_right(vector(RDF,[]))                                         # needs scipy
             ()
 
         Over an inexact ring like ``RDF``, the coefficient matrix of a
         square system must be nonsingular::
 
             sage: A = matrix(RDF, 5, range(25))
             sage: b = vector(RDF, [1,2,3,4,5])
-            sage: A.solve_right(b)
+            sage: A.solve_right(b)                                                      # needs scipy
             Traceback (most recent call last):
             ...
             LinAlgError: Matrix is singular.
@@ -795,7 +795,7 @@ cdef class Matrix(Matrix1):
 
             sage: A = matrix(RDF, 5, range(25))
             sage: b = vector(RDF, [1,2,3,4])
-            sage: A.solve_right(b)
+            sage: A.solve_right(b)                                                      # needs sage.rings.finite_rings
             Traceback (most recent call last):
             ...
             ValueError: number of rows of self must equal degree of
@@ -1768,7 +1768,7 @@ cdef class Matrix(Matrix1):
 
         Although it is not too far off::
 
-            sage: (~M - M.pseudoinverse(algorithm='numpy')).norm() < 1e-14              # needs numpy
+            sage: (~M - M.pseudoinverse(algorithm='numpy')).norm() < 1e-14              # needs scipy
             True
 
         TESTS::
@@ -7359,7 +7359,7 @@ cdef class Matrix(Matrix1):
 
         The following example shows that :issue:`12595` has been resolved::
 
-            sage: # needs sage.rings.complex_double
+            sage: # needs scipy sage.rings.complex_double
             sage: m = Matrix(CDF, 8, [[-1, -1, -1, -1, 1, -3, -1, -1],
             ....:                     [1, 1, 1, 1, -1, -1, 1, -3],
             ....:                     [-1, 3, -1, -1, 1, 1, -1, -1],

src/sage/matrix/matrix_double_dense.pyx

@@ -299,7 +299,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
             [4.0 5.0 6.0]
             [7.0 8.0 9.0]
 
-            sage: A.determinant() < 10e-12
+            sage: A.determinant() < 10e-12                                              # needs scipy
             True
 
         TESTS::
@@ -850,7 +850,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
 
         Bogus values of the ``eps`` keyword will be caught::
 
-            sage: A.singular_values(eps='junk')
+            sage: A.singular_values(eps='junk')                                         # needs scipy
             Traceback (most recent call last):
             ...
             ValueError: could not convert string to float: ...
@@ -1012,6 +1012,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
 
         The results are immutable since they are cached.  ::
 
+            sage: # needs scipy
             sage: P, L, U = matrix(RDF, 2, 2, range(4)).LU()
             sage: L[0,0] = 0
             Traceback (most recent call last):
@@ -1214,6 +1215,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
         In this generalized eigenvalue problem, the homogeneous coordinates
         explain the output obtained for the eigenvalues::
 
+            sage: # needs scipy
             sage: A = matrix.identity(RDF, 2)
             sage: B = matrix(RDF, [[3, 5], [6, 10]])
             sage: A.eigenvalues(B)  # tol 1e-14
@@ -2907,6 +2909,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
         A small matrix that does not fit into any of the usual categories
         of normal matrices.  ::
 
+            sage: # needs scipy
             sage: A = matrix(RDF, [[1, -1],
             ....:                  [1,  1]])
             sage: A.is_normal()

src/sage/misc/session.pyx

@@ -291,6 +291,7 @@ def save_session(name='sage_session', verbose=False):
 
     Something similar happens for cython-defined functions::
 
+        sage: # needs sage.misc.cython
         sage: g = cython_lambda('double x', 'x*x + 1.5')
         sage: save_session(tmp_f, verbose=True)
         ...

src/sage/quivers/ar_quiver.py

@@ -1,4 +1,5 @@
 # sage_setup: distribution = sagemath-flint
+# sage.doctest: needs sage.graphs sage.modules
 r"""
 Auslander-Reiten Quivers
 """

src/sage/rings/valuation/valuation.py

@@ -988,7 +988,7 @@ def montes_factorization(self, G, assume_squarefree=False, required_precision=No
             sage: S.<x> = R[]
             sage: f = (x^6+2)^25 + 5
             sage: v = R.valuation()
-            sage: v.montes_factorization(f, assume_squarefree=True, required_precision=0)
+            sage: v.montes_factorization(f, assume_squarefree=True, required_precision=0)   # needs sage.geometry.polyhedron
             (x^50 + 2*5*x^45 + 5*x^40 + 5*x^30 + 2*x^25 + 3*5*x^20 + 2*5*x^10 + 2*5*x^5 + 5*x + 3 + 5) * (x^50 + 3*5*x^45 + 5*x^40 + 5*x^30 + (3 + 4*5)*x^25 + 3*5*x^20 + 2*5*x^10 + 3*5*x^5 + 4*5*x + 3 + 5) * (x^50 + 3*5*x^40 + 3*5*x^30 + 4*5*x^20 + 5*x^10 + 3 + 5)
 
         In this case, ``f`` factors into degrees 1, 2, and 5 over a totally ramified extension::
@@ -1000,7 +1000,7 @@ def montes_factorization(self, G, assume_squarefree=False, required_precision=No
             sage: S.<x> = R[]
             sage: f = (x^3 + 5)*(x^5 + w) + 625
             sage: v = R.valuation()
-            sage: v.montes_factorization(f, assume_squarefree=True, required_precision=0)           # needs sage.libs.flint
+            sage: v.montes_factorization(f, assume_squarefree=True, required_precision=0)           # needs sage.geometry.polyhedron sage.libs.flint
             ((1 + O(w^60))*x + 4*w + O(w^61)) * ((1 + O(w^60))*x^2 + (w + O(w^61))*x + w^2 + O(w^62)) * ((1 + O(w^60))*x^5 + w + O(w^61))
 
         REFERENCES: