Re: Converting {{a,b},{c,d}} to just {a,b},{c,d} (no enclosing parens) ?

*To*: mathgroup at smc.vnet.net*Subject*: [mg28783] Re: [mg28766] Converting {{a,b},{c,d}} to just {a,b},{c,d} (no enclosing parens) ?*From*: Ken Levasseur <Kenneth_Levasseur at uml.edu>*Date*: Sat, 12 May 2001 20:18:15 -0400 (EDT)*References*: <200105120000.UAA21293@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hello: You can do what you want with Sequence: In[1]:= seq1 = {{a, b}, {c, d}} seq2 = {{e, f}, {g, h}} Line[{Sequence @@ seq1, Sequence @@ seq2}] Out[1]= {{a, b}, {c, d}} Out[2]= {{e, f}, {g, h}} Out[3]= Line[{{a, b}, {c, d}, {e, f}, {g, h}}] However, it would seem to be much easer to just join the lists of pairs. In[4]:= Line[Join[seq1, seq2]] Out[4]= Line[{{a, b}, {c, d}, {e, f}, {g, h}}] Hope this helps. Ken Levasseur Math Sci. UMass Lowell aes wrote: > How can I convert a list of pairs, like > > {{a,b},{c,d},{e,f},. . . }} > > into just a sequence of pairs, i.e. > > {a,b}, {c,d}, {e,f}, . . . > > with no outer { }'s? > > Reason for doing this? Want to define a Line in the form > > Line[{pt1, pt2, pt3, pt4, pt5, pt6, . . . . . . }] > > where some of the points, say pt1 through pt4 are individually defined; > but then a sequence, say pt5 through pt20, are defined by a Table; then > pt21, etc are back to individual definitions. > > I know -- I could break these into a sequence of Lines -- but it would > be cleaner if there were a simple way to have one Line[ ] command with > all the points inside it.

**References**:**Converting {{a,b},{c,d}} to just {a,b},{c,d} (no enclosing parens) ?***From:*aes <siegman@stanford.edu>