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NIntegrate[Abs] bug in v5.1, not v5.0

• To: mathgroup at smc.vnet.net
• Subject: [mg64191] NIntegrate[Abs] bug in v5.1, not v5.0
• From: "Solomon, Joshua" <J.A.Solomon at city.ac.uk>
• Date: Sat, 4 Feb 2006 04:13:49 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

First, I establish that everything works in v5.0.

In[1]:=

f[x_]:=E^-(Sin[.1+x]^2)-E^-(Sin[.1-x]^2)


In[2]:=

{$Version,$ReleaseNumber}

Out[2]=

{5.0 for Mac OS X (June 10, 2003),0}


In[3]:=

Timing[NIntegrate[-f[x],{x,0,Pi/2},AccuracyGoal->1]]

Out[3]=

{0.001438 Second,0.125515}


In[4]:=

Timing[NIntegrate[Abs[f[x]],{x,0,Pi/2},AccuracyGoal->1]]

Out[4]=

{0.0015 Second,0.125515}


Now I try again in v5.1.

In[1]:=

f[x_]:=E^-(Sin[.1+x]^2)-E^-(Sin[.1-x]^2)


In[2]:=

{$Version,$ReleaseNumber}

Out[2]=

{5.1 for Mac OS X (October 25, 2004),0}

In[3]:=

Timing[NIntegrate[-f[x],{x,0,Pi/2},AccuracyGoal->1]]

Out[3]=

{0.001286 Second,0.125515}


In[4]:=

Timing[NIntegrate[Abs[f[x]],{x,0,Pi/2},AccuracyGoal->1]]


This produces no output for several minutes. Then the Kernel crashes. Any
ideas?

j
-- 
Joshua A. Solomon
http://www.staff.city.ac.uk/~solomon

• Follow-Ups:
  • Re: NIntegrate[Abs] bug in v5.1, not v5.0
    • From: Pratik Desai <pdesai1@umbc.edu>