Question about Normal[] and O[]
- To: mathgroup at smc.vnet.net
- Subject: [mg8537] Question about Normal[] and O[]
- From: sbecuwe at uia.ua.ac.be (Stefan.Becuwe)
- Date: Sat, 6 Sep 1997 23:16:08 -0400
- Sender: owner-wri-mathgroup at wolfram.com
The purpose of Normal[] is to "truncate a power series to give an
ordinary expression". I hoped it would just remove the O[] term,
but, for one reason or another, it does a bit more (as you can see in
Out[24]).
Question: is there a function that only removes the O[] term
(in Mathematica 2.2? 3.0?)
(I need that "3 - (1 + x)" and not "2 - x" ...)
If it would have been possible to do a substitution ( /. ) before the
Normal[] function, then the problem would have been solved, but
/. doesn't seem to work when there's an O[] term...
In[23]:= Series[1+3x^2+x^5,{x,-1,5}]
2 3 4 5
Out[23]= 3 - (1 + x) - 7 (1 + x) + 10 (1 + x) - 5 (1 + x) + (1 + x) +
6
> O[1 + x]
In[24]:= Normal[Series[1+3x^2+x^5,{x,-1,5}]]
2 3 4 5
Out[24]= 2 - x - 7 (1 + x) + 10 (1 + x) - 5 (1 + x) + (1 + x)
Stefan Becuwe