gh-40414: Add some missing "long time" annotations
    
Fix a few CI warnings by adding `# long time`, and speed up one test by
limiting the number of examples to a random subset.
    
URL: #40414
Reported by: Michael Orlitzky
Reviewer(s):

Author: Release Manager

src/doc/en/thematic_tutorials/vector_calculus/vector_calc_change.rst

@@ -138,6 +138,7 @@ the above call ``E.spherical_coordinates()``::
 These formulas are automatically used if we ask to plot the grid of spherical
 coordinates in terms of Cartesian coordinates::
 
+    sage: # long time
     sage: spherical.plot(cartesian, color={r:'red', th:'green', ph:'orange'})
     Graphics3d Object
 

src/doc/en/thematic_tutorials/vector_calculus/vector_calc_curvilinear.rst

@@ -232,6 +232,7 @@ The Laplacian of a scalar field::
 
 The Laplacian of a vector field::
 
+    sage: # long time
     sage: Du = laplacian(u)
     sage: Du.display()
     Delta(u) = ((r^2*d^2(u_r)/dr^2 + 2*r*d(u_r)/dr - 2*u_r(r, th, ph)
@@ -247,7 +248,7 @@ The Laplacian of a vector field::
 Since this expression is quite lengthy, we may ask for a display component by
 component::
 
-    sage: Du.display_comp()
+    sage: Du.display_comp()  # long time
     Delta(u)^1 = ((r^2*d^2(u_r)/dr^2 + 2*r*d(u_r)/dr - 2*u_r(r, th, ph) + d^2(u_r)/dth^2
      - 2*d(u_theta)/dth)*sin(th)^2 - ((2*u_theta(r, th, ph) - d(u_r)/dth)*cos(th)
      + 2*d(u_phi)/dph)*sin(th) + d^2(u_r)/dph^2)/(r^2*sin(th)^2)
@@ -260,6 +261,7 @@ component::
 
 We may expand each component::
 
+    sage: # long time
     sage: for i in E.irange():
     ....:     s = Du[i].expand()
     sage: Du.display_comp()

src/sage/combinat/symmetric_group_algebra.py

@@ -1313,6 +1313,7 @@ def ladder_idempotent(self, la):
         modules (which are the :meth:`Specht modules <specht_module>`
         and also projective modules)::
 
+            sage: # long time
             sage: SGA = SymmetricGroupAlgebra(QQ, 5)
             sage: for la in Partitions(SGA.n):
             ....:     idem = SGA.ladder_idempotent(la)

src/sage/doctest/forker.py

@@ -2197,6 +2197,7 @@ class should be accessed by the child process.
 
     EXAMPLES::
 
+        sage: # long time
         sage: from sage.doctest.forker import DocTestWorker, DocTestTask
         sage: from sage.doctest.sources import FileDocTestSource
         sage: from sage.doctest.reporting import DocTestReporter
@@ -2321,6 +2322,7 @@ def start(self):
 
         TESTS::
 
+            sage: # long time
             sage: from sage.doctest.forker import DocTestWorker, DocTestTask
             sage: from sage.doctest.sources import FileDocTestSource
             sage: from sage.doctest.reporting import DocTestReporter
@@ -2360,6 +2362,7 @@ def read_messages(self):
 
         EXAMPLES::
 
+            sage: # long time
             sage: from sage.doctest.forker import DocTestWorker, DocTestTask
             sage: from sage.doctest.sources import FileDocTestSource
             sage: from sage.doctest.reporting import DocTestReporter
@@ -2394,6 +2397,7 @@ def save_result_output(self):
 
         EXAMPLES::
 
+            sage: # long time
             sage: from sage.doctest.forker import DocTestWorker, DocTestTask
             sage: from sage.doctest.sources import FileDocTestSource
             sage: from sage.doctest.reporting import DocTestReporter

src/sage/dynamics/arithmetic_dynamics/projective_ds.py

@@ -6972,7 +6972,7 @@ def Lattes_to_curve(self, return_conjugation=False, check_lattes=False):
             sage: P.<x,y>=ProjectiveSpace(QQbar, 1)
             sage: E=EllipticCurve([1, 2])
             sage: f=P.Lattes_map(E, 2)
-            sage: f.Lattes_to_curve(check_lattes=true)
+            sage: f.Lattes_to_curve(check_lattes=true)  # long time
             Elliptic Curve defined by y^2 = x^3 + x + 2 over Rational Field
 
         """

src/sage/graphs/hypergraph_generators.py

@@ -304,7 +304,7 @@ def BinomialRandomUniform(self, n, k, p):
 
         EXAMPLES::
 
-            sage: hypergraphs.BinomialRandomUniform(50, 3, 1).num_blocks()              # needs numpy
+            sage: hypergraphs.BinomialRandomUniform(50, 3, 1).num_blocks()              # needs numpy, long time
             19600
             sage: hypergraphs.BinomialRandomUniform(50, 3, 0).num_blocks()              # needs numpy
             0

src/sage/groups/perm_gps/permgroup_named.py

@@ -3505,16 +3505,24 @@ class SmallPermutationGroup(PermutationGroup_generic):
         Group of order 12 and GAP Id 4 as a permutation group
         sage: G.gens()
         ((4,5), (1,2), (3,4,5))
-        sage: G.character_table()                                                       # needs sage.rings.number_field
+        sage: G.character_table()  # needs sage.rings.number_field
         [ 1  1  1  1  1  1]
         [ 1 -1  1 -1  1 -1]
         [ 1 -1  1  1 -1  1]
         [ 1  1  1 -1 -1 -1]
         [ 2  0 -1 -2  0  1]
         [ 2  0 -1  2  0 -1]
         sage: def numgps(n): return ZZ(libgap.NumberSmallGroups(n))
-        sage: all(SmallPermutationGroup(n,k).id() == [n,k]
-        ....:     for n in [1..64] for k in [1..numgps(n)])  # long time (180s)
+        sage: # verify at most five n and k, randomly, to save time
+        sage: from random import sample
+        sage: ns = sample([1..64], 5)
+        sage: def ks(n):
+        ....:     ngps = numgps(n)
+        ....:     ssize = min(5, ngps)
+        ....:     return sample([1..ngps], ssize)
+        sage: all(SmallPermutationGroup(n,k).id() == [n,k]  # long time
+        ....:     for n in ns
+        ....:     for k in ks(n))
         True
         sage: H = SmallPermutationGroup(6,1)
         sage: H.is_abelian()

src/sage/interacts/test_jupyter.rst

@@ -205,7 +205,7 @@ Test all interacts from the Sage interact library::
     Exact value of the integral \(\displaystyle\int_{0}^{2}x^{2} +
     1\,\mathrm{d}x=4.666666666666668\)
 
-    sage: test(interacts.calculus.function_tool)
+    sage: test(interacts.calculus.function_tool)  # long time
     ...Interactive function <function function_tool at ...> with 7 widgets
       f: EvalText(value='sin(x)', description='f')
       g: EvalText(value='cos(x)', description='g')
@@ -218,7 +218,7 @@ Test all interacts from the Sage interact library::
     <center><font color="green">\(g = \cos\left(x\right)\)</font></center>
     <center><font color="blue"><b>\(h = f = \sin\left(x\right)\)</b></font></center>
 
-    sage: test(interacts.fractals.mandelbrot)
+    sage: test(interacts.fractals.mandelbrot)  # long time
     ...Interactive function <function mandelbrot at ...> with 6 widgets
       expo: FloatSlider(value=2.0, description='expo', max=10.0, min=-10.0)
       iterations: IntSlider(value=20, description='# iterations', min=1)
@@ -229,7 +229,7 @@ Test all interacts from the Sage interact library::
     <h2>Mandelbrot Fractal</h2>
     Recursive Formula: \(z \leftarrow z^{2.00} + c\) for \(c \in \mathbb{C}\)
 
-    sage: test(interacts.fractals.julia)
+    sage: test(interacts.fractals.julia)  # long time
     ...Interactive function <function julia at ...> with 8 widgets
       expo: FloatSlider(value=2.0, description='expo', max=10.0, min=-10.0)
       c_real: FloatSlider(value=0.5, description='real part const.', max=2.0, min=-2.0, step=0.01)
@@ -265,7 +265,7 @@ Test all interacts from the Sage interact library::
     \(AB = 1.931852\), \(BC = 1.732051\), \(CA = 1.414214\)
     Area of triangle \(ABC = 1.183013\)
 
-    sage: test(interacts.geometry.special_points)
+    sage: test(interacts.geometry.special_points)  # long time
     ...Interactive function <function special_points at ...> with 10 widgets
       title: HTMLText(value='<h2>Special points in triangle</h2>')
       a0: IntSlider(value=30, description='A', max=360)