Re: Segregating the elements of a list based on given lower and upper bounds

*To*: mathgroup at smc.vnet.net*Subject*: [mg77304] Re: [mg77205] Segregating the elements of a list based on given lower and upper bounds*From*: "R.G" <gobiithasan at yahoo.com.my>*Date*: Wed, 6 Jun 2007 07:24:17 -0400 (EDT)

Hi, Thank you for your answer. Now lets change the lists as: A = {6.32553, 7.09956, 8.56784, 16.1871, 15.3989, 17.2285, 7.40711, 14.8876, 19.9068, 10.0834, 12.000}; B = {{0, 7}, {7, 11}, {11, 12}, {12, 15}, {15, 20}}; where the the first bound defined as 0<=i<7, it applies to the rest. I have written the following code for segregating the list: f[x_, y_] := Rest[FoldList[If[#2 >= x && #2 < y, Sow[#2], Null] &, 1,A]] Table[class[i] = Delete[f[B[[i, 1]], B[[i, 2]]], Position[f[B[[i, 1]], B[[i, 2]]], Null]], {i, 1, Length[B]}]; Table[Length[class[i]], {i, 1, Length[B]}] It does the segregation as I wanted: {1, 4, 0, 2, 4}. However, if Length[A]=10,000, then it's quite slow. Is the code proper/efficient? Thanks, R.G. --- János <janos.lobb at yale.edu> wrote: > Here is a newbie approach: > /Your bounds do not correspond to the distribution you desire :)/ > > I use lower case a,b,c > > In[2]:= > sa = Sort[a] > > In[4]:= > c = Last[Reap[i = 1; > While[i <= Length[sa], > j = 1; While[j <= > Length[b], > If[b[[j,1]] <= > sa[[i]] <= b[[j, > 2]], Sow[{b[[j]], > sa[[i]]}, j]; j++, > j++; Continue[]]; ]* > i++; ]]] > Out[4]= > {{{{0, 7}, 6.32553}}, > {{{8, 10}, 8.56784}}, > {{{13, 15}, 14.8876}}, > {{{16, 18}, 16.1871}, > {{16, 18}, 17.2285}}} > > From there the distribution: > > In[22]:= > ({#1[[1,1]], Length[ > #1]} & ) /@ c > Out[22]= > {{{0, 7}, 1}, {{8, 10}, 1}, > {{13, 15}, 1}, {{16, 18}, > 2}} > > János > P.S Those ranges where you do not have a value you can Union it in > with using Complement > > > -------------------------------- > "I wish developing great products was as easy as writing a check. If > > that were the case, Microsoft would have some great products." > --Steve Jobs > > > > Send instant messages to your online friends http://uk.messenger.yahoo.com

**Follow-Ups**:**Re: Re: Segregating the elements of a list based on given lower and upper bounds***From:*János <janos.lobb@yale.edu>