[R] cut - strange NA as output

[Marc Schwartz]

> On Oct 6, 2015, at 2:20 PM, Hermann Norpois <hnorpois at gmail.com> wrote:
> 
> Hello,
> 
> why do I get NA for the following:
> 
> cut (x, seq (0, max(x), by=1), label=FALSE)
> [1] 1322 1175 1155 1149 1295 1173 1289 1197   NA 1129
> 
> dput (x)
> c(1321.55376901374, 1174.35657200935, 1154.02042504008, 1148.60981925942,
> 1294.6166388941, 1172.45806806869, 1288.31933914639, 1196.26080041462,
> 1355.88836502166, 1128.09901883228)
> 
> Thanks
> Hermann


> max(x)
[1] 1355.888

> range(seq(0, max(x), by = 1))
[1]    0 1355


max(x) is outside (above) the range of the integer sequence of break points for cut() that you specified above. Thus, when cut() gets to the 9th element in x, the value is undefined.

> cut (x, seq(0, max(x) + 1, by = 1), label=FALSE)
 [1] 1322 1175 1155 1149 1295 1173 1289 1197 1356 1129

or

> cut (x, seq(0, ceiling(max(x)), by = 1), label=FALSE)
 [1] 1322 1175 1155 1149 1295 1173 1289 1197 1356 1129


Both of the above approaches will increment the sequence 0:max(x) to 1356:

> range(seq(0, max(x) + 1, by = 1))
[1]    0 1356

> range(seq(0, ceiling(max(x)), by = 1))
[1]    0 1356


Regards,

Marc Schwartz