[R] if else for cumulative sum error

[David Winsemius]

On Dec 2, 2014, at 10:08 AM, Jefferson Ferreira-Ferreira wrote:

> Hello everybody;
> 
> I'm writing a code where part of it is as follows:
> 
> for (i in nrow(dadosmax)){
>  dadosmax$enchday[i] <- if (sum(dadosmax$above[i:(i+44)]) >= 45) 1 else 0
> }
> 
> That is for each row of my data frame, sum an specific column (0 or 1) of
> that row plus 44 rows. If It is >=45 than enchday is 1 else 0.
> 
> The following error is returned:
> 
> Error in if (sum(dadosmax$above[i:(i + 44)]) >= 45) 1 else 0 :
>  missing value where TRUE/FALSE needed
> 
> I've tested the ifelse statement assigning different values to i and it
> works. So I'm wondering if this error is due the fact that at the final of
> my data frame there aren't 45 rows to sum anymore. I tried to use "try" but
> It's simply hide the error.
> 
> How can I deal with this? Any ideas?

You should think about what would happen at the high end of values (for what is now being erroneously coded) for `nrow(dadosmax)` which a assume was meant to be `1:nrow(dadosmax)`. Should have been `seq_along(rownames(dadosmax))`. But even if that error were fixed you would be referencing non-existent rows as soon as you were within 44 rows of the end of the dataframe.

-- 
David.


> Thank you very much.
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius
Alameda, CA, USA