Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx02.iad01.newshosting.com!newshosting.com!newspump.sol.net!posts.news.twtelecom.net!nnrp3.twtelecom.net!not-for-mail From: Peter Breitfeld Newsgroups: comp.soft-sys.math.mathematica Subject: Re: get a, b from numbers in the form a+b Pi Date: Mon, 23 May 2011 10:28:47 +0000 (UTC) Organization: Steven M. Christensen and Associates, Inc and MathTensor, Inc. Sender: steve@smc.vnet.net Approved: Steven M. Christensen , Moderator Message-ID: References: Lines: 35 NNTP-Posting-Date: 23 May 2011 09:29:50 GMT NNTP-Posting-Host: e5dcb985.news.twtelecom.net X-Trace: DXC=UUOJA^I7KQSG[n\L2_@9VQC_A=>8kQj6]=_1NR_H?JP]_X2V7Zo>d=\EFiONJ7[GoVEFkGaDLQoWR X-Complaints-To: abuse@twtelecom.net Xref: x330-a1.tempe.blueboxinc.net comp.soft-sys.math.mathematica:2647 "1.156" wrote: > I have lists of numbers (Mathematica output) all numerically in the > form a + b*Pi and I'm trying to extract the values of a and b for > further work. > > Here's an example of the best I've been able to do so far: > > nums={1/2 (-2+\[Pi]),-2+(3 \[Pi])/4,-(11/3)+(5 \[Pi])/4,5/48 (-64+21 > \[Pi]),-(61/5)+(63 \[Pi])/16,-(338/15)+(231 \[Pi])/32}; > {FullForm[#][[1,1]],FullForm[#][[1,2]]/\[Pi]}&/@nums > > When I run this line of code 4 of the six input numbers give me the > {a,b} I'm looking for but the first and fourth entries fail because the > form isn't right. Possibly I could patch this scheme to look for a small > finite set of possibilities of input number form but I suspect I may a > long way from attacking this problem correctly. > > Can someone offer some other ideas on how to pull this off? Many thanks > for looking at this. Rob > -- > Sent from my plain desktop PC. > Try this: abRule = a_. + b_. Pi :> {a, b} Expand[nums] % /. abRule -- _________________________________________________________________ Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de