Re: Extract Integers

*To*: mathgroup at smc.vnet.net*Subject*: [mg131425] Re: Extract Integers*From*: Daniel <dosadchy at its.jnj.com>*Date*: Sun, 21 Jul 2013 21:40:56 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net

Since Rational[] is an Atom (AtomQ[2/3] returns True), Cases[] does not descent into it. You can use this: Cases[Cases[equ, v_?NumericQ, Infinity] /. Rational[e1_, e2_] -> Sequence[e1, e2], _Integer] Depending on your problem, you might want to treat Complex[] the same way. > Hi. I've run out of ideas. Does anyone know the > proper way to extract all the integers from the > following simplified version of a larger problem I'm > working on? > > equ=Series[Exp[x],{x,0,5}] //Normal > > 1+x+x^2/2+x^3/6+x^4/24+x^5/120 > > When trying to extract all the integers, I understand > numbers like 120 are part of Rational[1,120] > > equ //FullForm > > << Not shown here >> > > I thought looking at all LevelSpec was the solution, > but apparently not. > > Cases[equ, _Integer, Infinity] > {1,2,3,4,5} > > (* Or *) > > Position[equ, _Integer, Infinity] > {{1},{3,2,2},{4,2,2},{5,2,2},{6,2,2}} > > Extract[equ, %] > {1,2,3,4,5} > > Both ways extract from the numerator, but I just > can't seem to extract the {2,6,24,120} inside the > denominator. > Does anyone know the proper way? > Thanks in advance. :>~ > > Dana > Mac & Math 9 > >