Re: ExponentFunction

*To*: mathgroup at smc.vnet.net*Subject*: [mg24511] Re: [mg24451] ExponentFunction*From*: "Atul Sharma" <atulksharma at yahoo.com>*Date*: Thu, 20 Jul 2000 03:01:48 -0400 (EDT)*References*: <8l3fqv$l03@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Stan Wagon (Mathematica in Action, Telos 1997) defined a nice function which outputs the results of FactorInteger in prime factor-exponent form. Modifying it slightly to include the dot separator gives a pretty output: displayFactorInteger::usage = "displayFactorInteger[f] displays the list f, of the form returned by \ FactorInteger, as a list of individual prime factors with superscripted \ exponents separated by a dot." ; displayFactorInteger[l_] := SequenceForm @@ ( (DisplayForm[RowBox[{#1, "."}]] & ) /@ (MapThread[ If[#2 == 1, If[Head[#1] === Complex, StringJoin["(", ToString[#1], ")"], ToString at #1], SuperscriptBox[ToString at #1, #2]] &, Transpose[l]])); In[2]:=FactorInteger[100!] // displayFactorInteger Atul BobHanlon at aol.com wrote in message <8l3fqv$l03 at smc.vnet.net>... > >In a message dated 7/18/2000 2:03:01 AM, greg at mira.net writes: > >>I just thought of another quick question I'd like to throw in while I'm >>in the newsreader: I'm having trouble composing an elegant functional way >>of >>converting the results of FactorInteger into a form where all the factors >>(with multiples) are strung together dot separated (example >>2.2.2.3.3.43.1181). Any ideas? > >x = 2*2*2*3*3*43*1181; > >Dot @@ Flatten[Table[#[[1]], {#[[2]]}] & /@ FactorInteger[x]] > >2 . 2 . 2 . 3 . 3 . 43 . 1181 > >Times @@ % == x > >True > > >Bob Hanlon >