Re: get a, b from numbers in the form a+b Pi
- To: mathgroup at smc.vnet.net
- Subject: [mg119140] Re: get a, b from numbers in the form a+b Pi
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Mon, 23 May 2011 06:23:19 -0400 (EDT)
I forgot that you wanted only the a and the b, not the Pi. The following will do what you want -- again only in the case that both a and b are nonzero: Through[{First, (Last[#]/Pi &)}[#]] & /@ Expand[nums] On 5/22/2011 6:57 AM, 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 -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305