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Re: normalized ALF (Assotiated Legendre Function)
From: |
Marco Caliari |
Subject: |
Re: normalized ALF (Assotiated Legendre Function) |
Date: |
Wed, 13 Feb 2008 14:16:24 +0100 (CET) |
That line was incorporated from your version. Should it be something else?
Something like that to be added:
if (max(abs(scale)) == Inf)
underflow = true;
endif
and try to prevent that scale becomes Inf.
Moreover, I don't understand the limit 255 on n. With the normalizations,
there are no problems for n>255.
Agreed.
The enclosed version has a further improvement:
# the warning when scale is Inf
octave:4> legendre(151,0)(end)
warning: legendre: results may be unstable for high orders.
warning: legendre: results may be unstable for high orders.
ans = -Inf
octave:5> legendreold(151,0)(end)
ans = -Inf
# NaN prevented in case of Inf*0
octave:8> legendre(151,-1)(end-1:end)
ans =
-0
-0
octave:9> legendreold(151,-1)(end-1:end)
ans =
-0
NaN
# Inf prevented in case of Inf*(small quantity)
octave:10> legendre(151,-0.9)(end-1:end)
ans =
-8.1986e+254
-3.9708e+254
octave:11> legendreold(151,-0.9)(end-1:end)
ans =
-8.1986e+254
-Inf
Best regards,
Marco
legendre.m
Description: Text document
- Re: normalized ALF (Assotiated Legendre Function), (continued)
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/11
- Re: normalized ALF (Assotiated Legendre Function), Dmitri A. Sergatskov, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Marco Caliari, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Marco Caliari, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Marco Caliari, 2008/02/13
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/13
- Re: normalized ALF (Assotiated Legendre Function),
Marco Caliari <=
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/13
- Re: normalized ALF (Assotiated Legendre Function), Marco Caliari, 2008/02/13
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/13
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/13
- Re: normalized ALF (Assotiated Legendre Function), Marco Caliari, 2008/02/14
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/14
- Re: normalized ALF (Assotiated Legendre Function), Marco Caliari, 2008/02/12
- Re: normalized ALF (Assotiated Legendre Function), Ben Abbott, 2008/02/12