Recent changes to 399: Infinite loop in Taylor(asin(sqrt(1-x^2)/(1+eps))...)/workarhttp://sourceforge.net/p/maxima/bugs/399/Recent changes to 399: Infinite loop in Taylor(asin(sqrt(1-x^2)/(1+eps))...)/workarenTue, 09 Sep 2003 15:51:00 -0000Infinite loop in Taylor(asin(sqrt(1-x^2)/(1+eps))...)/workarhttp://sourceforge.net/p/maxima/bugs/399/forwarded 198466 maxima@math.utexas.edu
tags 198466 +upstream
tags 198466 +confirmed
thanks
A Debian user submitted this report, which I'm also
registering at the
website. Any ideas on a fix?
Take care,
=============================================================================
When trying to do some complicated Taylor series
expansions, maxima
hangs; I believe it is in an infinite loop, as xload
shows the cpu
saturated.
An example is:
f\(x\):= asin\(sqrt\(1-x^2\)/\(1+eps\)\);
taylor\(f\(x\),x,0,2\);
which produces this condition. While trying to isolate
the bug, I tried:
g\(x\):=asin\(sqrt\(1-x^2\)\);
taylor\(g\(x\),x,0,2\);
which produces the error message:
&quot;Taylor encountered an unfamiliar singularity in ABS\(X\)&quot;
I am unable to find any documentation on this
&quot;unfamiliar singularity&quot;
error message. However, from looking at the second
derivative of G\(x\),
I think I can see what's causing the problem: the
sqrt\(\) in the above
expression is symmetrical about x=0, but has a cusp
there. However, this
ought to cause taylor\(\) to produce an error message in
the first example,
instead of looping; this is not very user-friendly.
What's the difference between a familiar singularity
and an unfamiliar
one, anyway?
=============================================================================
\--
Camm Maguire camm@enhanced.com
==========================================================================
&quot;The earth is but one country, and mankind its
citizens.&quot; -- Baha'u'llah
Camm MaguireTue, 09 Sep 2003 15:51:00 -0000http://sourceforge.net1daf14ae627222dd1d7442d0560137c7fd4cd177