[R] is a sequence of dates consecutive, without gaps?

[Marc Schwartz]

On Jul 21, 2009, at 4:58 PM, Christopher W. Ryan wrote:

> I have a long sequence of dates, about 6 years worth, as one column  
> in a
> data frame. How can I test whether the sequence is consecutive, that  
> is,
> without gaps?
>
> Thanks.
>
> --Chris


Chris,

Presuming that your data frame is called DF, the date column is called  
'date' AND 'date' has been coerced to a Date class, you could use:

   all(diff(DF$date) == 1)

which will tell you if all of the differences between successive dates  
in the column are one day.

See ?diff for more information.

If the dates have not yet been coerced to a Date class, see ?as.Date.

HTH,

Marc Schwartz