# Re: [R] Max consecutive increase in sequence

From: Tony Plate <tplate_at_acm.org>
Date: Tue, 13 May 2008 21:07:34 -0600

``` > x <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1)
> r <- rle(sign(diff(x)))
> r
```

Run Length Encoding

lengths: int [1:5] 3 2 2 5 4
values : num [1:5] 1 0 1 -1 0
> i1 <- which(r\$lengths==max(r\$lengths[r\$values==1]) & r\$values==1)[1]
> i2 <- which(r\$lengths==max(r\$lengths[r\$values==-1]) & r\$values==-1)[1]
> i1
[1] 1
> i2
[1] 4
> rbind(up=c(start=cumsum(c(1, r\$lengths))[i1], len=r\$lengths[i1]), down=c(start=cumsum(c(1, r\$lengths))[i2], len=r\$lengths[i2]))

```      start len
up       1   3
down     8   5
```

>

Ingmar Visser wrote:

```> rle(diff(sq)) could be helpful here,
> best, Ingmar
>
> On May 13, 2008, at 11:19 PM, Marko Milicic wrote:
>
```

>> Hi all R helpers,
>>
>> I'm trying to comeup with nice and elegant way of "detecting" consecutive
>> increases/decreases in the sequence of numbers. I'm trying with
>> combination
>> of which() and diff() functions but unsuccesifuly.
>>
>> For example:
>>
>> sq <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1);

>>
>> I'd like to find way to calculate
>>
>> a) maximum consecutive increase = 3 (from 1 to 4)
>> b) maximum consecutive decrease = 5 (from 6 to 1)
>>
>> All ideas are highly welcomed!
>>
>>
>>
>>
>>
>> --
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```>
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