Hi,
I have written the following function to check whether a vector has elements
satisfying monotonicity.
is.monotone <- function(vec, increase=T){
# check for monotonicity in time-stamp data for cortisol collection
ans <- TRUE
vec.nomis <- vec[!is.na(vec)]
if (increase & any(diff(vec.nomis,1) < 0, na.rm=T)) ans <- FALSE
if (!increase & any(diff(vec.nomis,1) > 0, na.rm=T)) ans <- FALSE
ans
}
This works correctly, but I get this error message as below.
> x <- 2:10
> is.monotone(x)
[1] TRUE
Warning messages:
1: the condition has length > 1 and only the first element will be used in:
if (increase & any(diff(vec.nomis, 1) < 0, na.rm = T)) ans <- FALSE
2: the condition has length > 1 and only the first element will be used in:
if (!increase & any(diff(vec.nomis, 1) > 0, na.rm = T)) ans <- FALSE
>
I am unable to see why the condition should have a length greater than 1,
since "any" should give me a single logical value.
Can any one tell me what is going on here? ( I am using version 2.1.1 on
Windows).
Thanks very much,
Ravi.
--------------------------------------------------------------------------
Ravi Varadhan, Ph.D.
Assistant Professor,?? The Center on Aging and Health
Division of Geriatric Medicine and Gerontology
Johns Hopkins University
Ph: (410) 502-2619
Fax: (410) 614-9625
Email:?? rvaradhan at jhmi.edu
Ravi Varadhan <RVARADHAN at jhmi.edu> writes:> Hi, > > I have written the following function to check whether a vector has elements > satisfying monotonicity. > > is.monotone <- function(vec, increase=T){ > # check for monotonicity in time-stamp data for cortisol collection > ans <- TRUE > vec.nomis <- vec[!is.na(vec)] > if (increase & any(diff(vec.nomis,1) < 0, na.rm=T)) ans <- FALSE > if (!increase & any(diff(vec.nomis,1) > 0, na.rm=T)) ans <- FALSE > ans > } > > This works correctly, but I get this error message as below. > > > x <- 2:10 > > is.monotone(x) > [1] TRUE > Warning messages: > 1: the condition has length > 1 and only the first element will be used in: > if (increase & any(diff(vec.nomis, 1) < 0, na.rm = T)) ans <- FALSE > 2: the condition has length > 1 and only the first element will be used in: > if (!increase & any(diff(vec.nomis, 1) > 0, na.rm = T)) ans <- FALSE > > > > I am unable to see why the condition should have a length greater than 1, > since "any" should give me a single logical value. > > Can any one tell me what is going on here? ( I am using version 2.1.1 on > Windows).Would you happen to have a variable called "T" around? -- O__ ---- Peter Dalgaard ??ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907