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

• To: mathgroup at smc.vnet.net
• Subject: [mg77265] Re: [mg77205] Segregating the elements of a list based on given lower and upper bounds
• From: János <janos.lobb at yale.edu>
• Date: Wed, 6 Jun 2007 07:04:02 -0400 (EDT)
• References: <200706051058.GAA01759@smc.vnet.net>

On Jun 5, 2007, at 6:58 AM, R.G wrote:

> Hi Mathgroup members,
>
> Say, I have a list with the following elements:
>
> A={6.32553, 7.09956, 8.56784, 16.1871, 15.3989, 17.2285, 7.40711, \
> 14.8876, 19.9068, 10.0834}
>
> and I have the following list with each {xvalue, yvalue}={lower =
bound,
> upper bound}:
>  B={{0, 7}, {8, 10}, {11, 12}, {13, 15}, {16, 18}}
>
> How can I segregate values in A according to lower bound and upper
> bound from B and find the number number of occurrence ?For example:
> {0,7}={6.32553}, thus the number of occurrence is 1.
> {8, 10}={7.09956,7.40711,8.56784}, the number of occurrence is 3.
> {11,12}=None, the number of occurrence is 0.
>
> The code should be able work for any number Length[A] and Length[B].
> Any suggestion please?
> Thank you,
> R.G
>

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}}}

 =46rom 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}}

J=E1nos
P.S  Those ranges where you do not have a value you can Union it in 
with using Complement


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• References:
  • Segregating the elements of a list based on given lower and upper bounds
    • From: "R.G" <gobiithasan@yahoo.com.my>