# [R] How to search for a sequence(and its combination) inside a vector?

C W tmrsg11 at gmail.com
Sat Jul 20 18:36:55 CEST 2013

```Hi Berend
I am looking for a table,
# of times one element (out of 1, 2, 3) showed up, two elements, and all three.

I am trying, don't know if this works:

> aa <- rle(a)
> b <- aa\$lengths[aa\$values]
> table(b)
b
1  3
3 12

Mike

On Sat, Jul 20, 2013 at 12:24 PM, Berend Hasselman <bhh at xs4all.nl> wrote:
>
> On 20-07-2013, at 18:05, C W <tmrsg11 at gmail.com> wrote:
>
>> Hi R list,
>>
>> I have a sequence repeating 1:15 .  Some numbers are deleted.  I want
>> to find how many times 1, 2, 3 appeared.
>> Basically, I want to "grab" the beginning of the sequence and tally it up.
>>
>> R code:
>>
>>> vec <- c(1, 2, 3, 4, 5, 6, 7, 8, 13, 1, 2, 3, 5, 7, 8, 10, 12, 13, 14,
>> 15, 1, 2, 3, 5, 6, 10, 12, 13, 1, 2, 3, 4, 5, 6, 7, 12, 13, 14,
>> 15, 1, 2, 3, 6, 9, 10, 11, 13, 14, 1, 7, 10, 13, 1, 2, 3, 4,
>> 6, 7, 9, 11, 14, 1, 2, 3, 5, 9, 10, 11, 12, 14, 1, 2, 3, 4, 1,
>> 2, 3, 4, 11, 12, 14, 1, 2, 3, 4, 8, 11, 12, 1, 2, 3, 4, 5, 7,
>> 8, 9, 11, 12, 15, 3, 14, 1, 2, 3, 6, 10, 11, 13, 14, 1)
>>
>>> a <- vec %in% c(1, 2, 3)
>>> a
>>  [1]  TRUE  TRUE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE
>> TRUE  TRUE FALSE FALSE
>> [15] FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE FALSE
>> FALSE FALSE FALSE FALSE
>> [29]  TRUE  TRUE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
>> FALSE  TRUE  TRUE  TRUE
>> [43] FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE FALSE FALSE
>> TRUE  TRUE  TRUE FALSE
>> [57] FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE FALSE FALSE
>> FALSE FALSE FALSE FALSE
>> [71]  TRUE  TRUE  TRUE FALSE  TRUE  TRUE  TRUE FALSE FALSE FALSE
>> FALSE  TRUE  TRUE  TRUE
>> [85] FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE FALSE FALSE FALSE
>> FALSE FALSE FALSE FALSE
>> [99] FALSE  TRUE FALSE  TRUE  TRUE  TRUE FALSE FALSE FALSE FALSE FALSE  TRUE
>>
>>> rle(a)
>> Run Length Encoding
>>  lengths: int [1:29] 3 6 3 8 3 5 3 8 3 6 ...
>>  values : logi [1:29] TRUE FALSE TRUE FALSE TRUE FALSE ...
>>
>> What should I do after this?
>>
>
>
> sum(a)
>
> or
>
> b <- rle(a)
> sum(b\$lengths[b\$values])
>
> Berend
>
>> Thanks,
>> Mike
>>
>> ______________________________________________
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