#13271: wrong sign with function Ei and limit
---------------------------------+------------------------------------------
Reporter: dkrenn | Owner: burcin
Type: defect | Status: new
Priority: major | Milestone: sage-5.3
Component: symbolics | Resolution:
Keywords: Ei limit sign | Work issues:
Report Upstream: N/A | Reviewers:
Authors: | Merged in:
Dependencies: | Stopgaps:
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Comment (by kcrisman):
Huh.
Apply
{{{
#!diff
diff --git a/sage/interfaces/maxima_lib.py b/sage/interfaces/maxima_lib.py
--- a/sage/interfaces/maxima_lib.py
+++ b/sage/interfaces/maxima_lib.py
@@ -1165,7 +1165,6 @@
max_psi=EclObject("$PSI")
max_array=EclObject("ARRAY")
mdiff=EclObject("%DERIVATIVE")
-max_gamma_incomplete=sage_op_dict[sage.functions.other.gamma_inc]
max_lambert_w=sage_op_dict[sage.functions.log.lambert_w]
def mrat_to_sage(expr):
@@ -1358,7 +1357,6 @@
sage.functions.log.polylog : lambda N,X : [[mqapply],[[max_li,
max_array],N],X],
sage.functions.other.psi1 : lambda X : [[mqapply],[[max_psi,
max_array],0],X],
sage.functions.other.psi2 : lambda N,X : [[mqapply],[[max_psi,
max_array],N],X],
- sage.functions.exp_integral.Ei : lambda X : [[max_gamma_incomplete],
0, X],
sage.functions.log.lambert_w : lambda N,X : [[max_lambert_w], X] if
N==EclObject(0) else [[mqapply],[[max_lambert_w, max_array],N],X]
}
}}}
to get
{{{
sage: var('Z')
Z
sage: (Ei(-Z)).limit(Z=oo)
0
sage: (Ei(-Z)).limit(Z=1000)
Ei(-1000)
sage: (Ei(-Z)).limit(Z=1000).n()
-5.07089306023517e-438
}}}
Tests look good.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13271#comment:5>
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