seq.int does not return a sequence of integers sometimes - R-devel

Wed, Aug 3, 2016 1:12 PM #

I have a script that goes wrong because I assumed that seq.int would
return integers.

Below please see it does not unless user is super cautious about
inserting "L" with inputs. I think seq.int should do coercion for me
before returning the sequence.

[1] "integer"

[1] TRUE

[1] "numeric"

[1] FALSE

[1] "numeric"

[1] FALSE

[1] "integer"

[1] TRUE


I think all of those should have same return value, if the function is
correctly named seq.int.

Paul E. Johnson   http://pj.freefaculty.org
Director, Center for Research Methods and Data Analysis http://crmda.ku.edu

I only use this account for email list memberships. To write directly,
address me at pauljohn at ku.edu.

Marc Schwartz

Wed, Aug 3, 2016 1:26 PM #

Paul,

?seq.int has the following:

under Details:

"seq.int is an internal generic which dispatches on methods for "seq" based on the class of the first supplied argument (before argument matching)."

and under Value:

"seq.int and the default method of seq for numeric arguments return a vector of type "integer" or "double": programmers should not rely on which."


So:

[1] FALSE

[1] TRUE

which would seem to explain the behavior that you are observing.

Regards,

Marc Schwartz

Duncan Murdoch

Wed, Aug 3, 2016 2:19 PM #

On 03/08/2016 4:12 PM, Paul Johnson wrote:

"int" means "internal", not "integer".  Sometimes you should read the 
documentation.

Duncan Murdoch