Relates to http://trac.sagemath.org/sage_trac/ticket/8983 erf0.patch
# return 0.0 for different fields sage: erf(0) 0.0 sage: erf(0.0) 0.0 sage: erf(CC(0)) 0.0 sage: erf(x) erf(x) sage: x=0; erf(x) 0.0
# The following are equivalent to those above? sage: erf(CC(0.0)) 0.0 sage: erf(RR(0.0)) 0.0 sage: erf(RR(0)) 0.0 sage: erf(ZZ(0)) 0.0
# timing without application of patch sage: %timeit t = erf(0) 625 loops, best of 3: 89.2 µs per loop sage: %timeit t = erf(0.0) 625 loops, best of 3: 166 µs per loop sage: %timeit t = erf(CC(0)) 625 loops, best of 3: 232 µs per loop sage: %timeit t = erf(CC(0.0)) 625 loops, best of 3: 253 µs per loop sage: %timeit t = erf(RR(0.0)) 625 loops, best of 3: 170 µs per loop sage: %timeit t = erf(RR(0)) 625 loops, best of 3: 158 µs per loop sage: %timeit t = erf(ZZ(0)) 625 loops, best of 3: 89 µs per loop sage: %timeit t = erf(x) 625 loops, best of 3: 90.4 µs per loop # timing after application of patch # ( testing for zero using is_zero() ) sage: %timeit t = erf(0) 625 loops, best of 3: 107 µs per loop sage: %timeit t = erf(0.0) 625 loops, best of 3: 120 µs per loop sage: %timeit t = erf(CC(0)) 625 loops, best of 3: 198 µs per loop sage: %timeit t = erf(CC(0.0)) 625 loops, best of 3: 220 µs per loop sage: %timeit t = erf(RR(0.0)) 625 loops, best of 3: 122 µs per loop sage: %timeit t = erf(RR(0)) 625 loops, best of 3: 111 µs per loop sage: %timeit t = erf(ZZ(0)) 625 loops, best of 3: 113 µs per loop sage: %timeit t = erf(x) 625 loops, best of 3: 106 µs per loop # timing after application of patch # ( testing for zero using "==0" ) sage: %timeit t = erf(0) 625 loops, best of 3: 135 µs per loop sage: %timeit t = erf(0.0) 625 loops, best of 3: 148 µs per loop sage: %timeit t = erf(CC(0)) 625 loops, best of 3: 231 µs per loop sage: %timeit t = erf(CC(0.0)) 625 loops, best of 3: 253 µs per loop sage: %timeit t = erf(RR(0.0)) 625 loops, best of 3: 145 µs per loop sage: %timeit t = erf(RR(0)) 625 loops, best of 3: 130 µs per loop sage: %timeit t = erf(ZZ(0)) 625 loops, best of 3: 126 µs per loop sage: %timeit t = erf(x) 625 loops, best of 3: 117 µs per loop
# # The one failure is in expression.pyx # [email protected]:~/sage-4.4.2$ ./sage -t devel/sage/sage/symbolic/expression.pyx sage -t "devel/sage/sage/symbolic/expression.pyx" ********************************************************************** File "/home/rossk/sage-4.4.2/devel/sage/sage/symbolic/expression.pyx", line 7082: sage: (cos(theta) - erf(theta)).plot((theta,-2*pi,2*pi)) Exception raised: Traceback (most recent call last): File "/home/rossk/sage-4.4.2/local/bin/ncadoctest.py", line 1231, in run_one_test self.run_one_example(test, example, filename, compileflags) File "/home/rossk/sage-4.4.2/local/bin/sagedoctest.py", line 38, in run_one_example OrigDocTestRunner.run_one_example(self, test, example, filename, compileflags) File "/home/rossk/sage-4.4.2/local/bin/ncadoctest.py", line 1172, in run_one_example compileflags, 1) in test.globs File "<doctest __main__.example_162[5]>", line 1, in <module> (cos(theta) - erf(theta)).plot((theta,-Integer(2)*pi,Integer(2)*pi))###line 7082: sage: (cos(theta) - erf(theta)).plot((theta,-2*pi,2*pi)) File "expression.pyx", line 7161, in sage.symbolic.expression.Expression.plot (sage/symbolic/expression.cpp:28597) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/plot/misc.py", line 283, in wrapper return func(*args, **kwds) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/plot/misc.py", line 138, in wrapper return func(*args, **options) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/plot/plot.py", line 2501, in plot G = _plot(funcs, *args, **kwds) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/plot/plot.py", line 2608, in _plot data = generate_plot_points(f, xrange, plot_points, adaptive_tolerance, adaptive_recursion, randomize) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/plot/plot.py", line 3596, in generate_plot_points data[i] = (float(xi), float(f(xi))) File "fast_eval.pyx", line 628, in sage.ext.fast_eval.FastDoubleFunc.__call__ (sage/ext/fast_eval.c:4495) File "fast_eval.pyx", line 636, in sage.ext.fast_eval.FastDoubleFunc._call_c (sage/ext/fast_eval.c:4575) File "fast_eval.pyx", line 432, in sage.ext.fast_eval.process_op (sage/ext/fast_eval.c:3058) File "function.pyx", line 431, in sage.symbolic.function.Function.__call__ (sage/symbolic/function.cpp:4528) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/functions/other.py", line 71, in _eval_ if x.is_zero(): AttributeError: 'float' object has no attribute 'is_zero' ********************************************************************** File "/home/rossk/sage-4.4.2/devel/sage/sage/symbolic/expression.pyx", line 2255: sage: v1=var('v1'); a = (2*erf(2*v1*arcsech(0))/v1); ~a Exception raised: Traceback (most recent call last): File "/home/rossk/sage-4.4.2/local/bin/ncadoctest.py", line 1231, in run_one_test self.run_one_example(test, example, filename, compileflags) File "/home/rossk/sage-4.4.2/local/bin/sagedoctest.py", line 38, in run_one_example OrigDocTestRunner.run_one_example(self, test, example, filename, compileflags) File "/home/rossk/sage-4.4.2/local/bin/ncadoctest.py", line 1172, in run_one_example compileflags, 1) in test.globs File "<doctest __main__.example_59[4]>", line 1, in <module> v1=var('v1'); a = (Integer(2)*erf(Integer(2)*v1*arcsech(Integer(0)))/v1); ~a###line 2255: sage: v1=var('v1'); a = (2*erf(2*v1*arcsech(0))/v1); ~a File "function.pyx", line 431, in sage.symbolic.function.Function.__call__ (sage/symbolic/function.cpp:4528) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/functions/other.py", line 71, in _eval_ if x.is_zero(): File "element.pyx", line 750, in sage.structure.element.Element.is_zero (sage/structure/element.c:5729) File "expression.pyx", line 1640, in sage.symbolic.expression.Expression.__nonzero__ (sage/symbolic/expression.cpp:8117) File "expression.pyx", line 1634, in sage.symbolic.expression.Expression.__nonzero__ (sage/symbolic/expression.cpp:8049) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/symbolic/relation.py", line 381, in test_relation_maxima m = relation._maxima_() File "expression.pyx", line 433, in sage.symbolic.expression.Expression._maxima_ (sage/symbolic/expression.cpp:3382) File "sage_object.pyx", line 386, in sage.structure.sage_object.SageObject._interface_ (sage/structure/sage_object.c:3501) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/interfaces/expect.py", line 1032, in __call__ return cls(self, x, name=name) File "/home/rossk/sage-4.4.2/local/lib/python/site-packages/sage/interfaces/expect.py", line 1451, in __init__ raise TypeError, x TypeError: Error executing code in Maxima CODE: sage934 : (v1)*(asech(0))*(2) = 0$ Maxima ERROR: The number 0 isn't in the domain of asech -- an error. To debug this try: debugmode(true); ********************************************************************** 2 items had failures: 1 of 15 in __main__.example_162 1 of 5 in __main__.example_59 ***Test Failed*** 2 failures. For whitespace errors, see the file /home/rossk/.sage//tmp/.doctest_expression.py [105.6 s] ---------------------------------------------------------------------- The following tests failed: sage -t "devel/sage/sage/symbolic/expression.pyx" Total time for all tests: 105.6 seconds --------------------------------
# the errors above seem to be contradicted by the statements below # The error of "The number 0 isn't in the domain of asech" seems contradicted by sage: asech(0) arcsech(0) sage: asech(0.0) +infinity # The error of "'float' object has no attribute 'is_zero'" seems contradicted by sage: (0.0).is_zero() True sage: RR(0).is_zero() True
