Re: Computing n-grams

*To*: mathgroup at smc.vnet.net*Subject*: [mg88960] Re: [mg88913] Computing n-grams*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 22 May 2008 02:37:41 -0400 (EDT)*Reply-to*: hanlonr at cox.net

Use Partition x = {a, b, c, d, e, f, g}; Partition[x, 2, 1] {{a, b}, {b, c}, {c, d}, {d, e}, {e, f}, {f, g}} Partition[x, 3, 1] {{a, b, c}, {b, c, d}, {c, d, e}, {d, e, f}, {e, f, g}} Bob Hanlon ---- "Coleman wrote: > Greetings, > > Imagine one has a list such as {a,b,c,d,e,f,g}. I'm trying to find an > efficient way in Mathematica to compute the n-grams of the list. That is, for > n=2, the n-grams are all the lists of length 2 consisting of consecutive > elements, e.g., > > {a,b},{b,c},{c,d},{d,e},... > > While for n=3, > > {a,b,c},{b,c,d},{c,d,e},..., and so on. > > As I understand it, the built-in Mathematica commands such as Subsets or > Permutations compute all possible list of size n, without regard to the > order of the list elements. > > Thanks, > > Mark > >