Re: newbie list question

*To*: mathgroup at smc.vnet.net*Subject*: [mg114995] Re: newbie list question*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Tue, 28 Dec 2010 06:47:37 -0500 (EST)

The following will do it: Flatten[First@Position[listA, #] & /@ listB] That's a "functional" method. Doubtless there's a (possibly simpler) pattern-matching method as well. On 12/26/2010 4:02 AM, Gareth Edwards wrote: > Hi, > > Liking Mathematica a lot, but struggling with the early part of the learning curve, i.e. don't know what I don't know... > > What would be the neatest syntax for finding the first location of elements from one list in another? For example: > > listA = { 4,5,8,2,6,4 } > listB = { 8,4,2 } > > > I would like a function to return {3,1,4} in this case (the first location in A of each element in B) > > Many thanks! > -- 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