selecting certain values from a list

I have this list below (call it A), and i wish to find the last value of a group of numbers. if you look at the numbers, they are bunched together in groups (not always consecutively), and i only want the last number in each group.

A =

           8
           9
         106
         107
         109
         110
         244
         245
         325
         326
         329
         334
         335
         483
         484
         485
         486
         527
         528
         690
         691

So the new list (call it B), should look like this..

B =

           9
         110
         245
         335
         486
         528
         691

I was thinking of making a for loop (i=1:length(A)) and doing a 'find' to see if a number exists in between that number and +20 after it (each new group of numbers never exceeds beyond 20).

is this possible? thank you in advance

Answer 1

[Paulo Silva]

M=[ 8 9 106 107 109 110 244 245 325 326 329 334 335 483 484 485 486 527 528 690 691]

    d=diff(M);       %find the diference between consecutive values
    [M(d>1);M(end)]  %get the values with diference bigger than 1

append M(end) because the last one is always the last from a group and the diference function doesn't catch it

[Nathan Greco]

Note the comment that says "they are bunched together in groups (not always consecutively)". Yours counts groups as consecutive, while the following is in actuality one group: 325 326 329 334 335.

[Oleg Komarov]

Andrei's solution applies well to your example data. The implicit rule is that the group is defined by the hundreds/thousands/so on digits.

[Sean de Wolski]

I think Paulo's code mended to be >20 as the OP said would be ideal.

[Oleg Komarov]

What if the numbers are: 398 399 400 401. Will the 3.. and the 4.. numbers be part of the same group or to separate?

[Sean de Wolski]

OP: "I was thinking of making a for loop (i=1:length(A)) and doing a 'find' to see if a number exists in between that number and +20 after it (each new group of numbers never exceeds beyond 20)."

so basically anywhere there's a gap of more than 20 it fails.

[Michael]

if the numbers are 398 399 400 401, then in my case they will all belong to the same group. these numbers in my case represent indices for a data set, and the gap between groups of data is usually higher than 100, and each different "cluster" of close numbers usually doesnt exceed 10, but i used 20 to be safe, with the intention of only gathering the last value of each group.

Answer 2

[Andrei Bobrov]

[a b c]=unique(floor(A/100));
out = A(b)

[Michael]

nice thinking, this worked, but for some reason when i added the longer list i have, one of them didnt show up..