which.min {base} | R Documentation |
Determines the location, i.e., index of the (first) minimum or maximum of a numeric (or logical) vector.
which.min(x) which.max(x)
x |
numeric (logical, integer or double) vector or an R object
for which the internal coercion to |
Missing and NaN
values are discarded.
an integer
or on 64-bit platforms, if
length(x) =: n
>= 2^31 an integer
valued double
of length 1 or 0 (iff x
has no
non-NA
s), giving the index of the first minimum or
maximum respectively of x
.
If this extremum is unique (or empty), the results are the same as
(but more efficient than) which(x == min(x, na.rm = TRUE))
or
which(x == max(x, na.rm = TRUE))
respectively.
For a logical
vector x
with both FALSE
and
TRUE
values, which.min(x)
and which.max(x)
return
the index of the first FALSE
or TRUE
, respectively, as
FALSE < TRUE
.
Martin Maechler
Use arrayInd()
, if you need array/matrix indices instead
of 1D vector ones.
which.is.max
in package nnet differs in
breaking ties at random (and having a ‘fuzz’ in the definition
of ties).
x <- c(1:4, 0:5, 11) which.min(x) which.max(x) ## it *does* work with NA's present, by discarding them: presidents[1:30] range(presidents, na.rm = TRUE) which.min(presidents) # 28 which.max(presidents) # 2 ## Find the first occurrence, i.e. the first TRUE, if there is at least one: x <- rpois(10000, lambda = 10); x[sample.int(50, 20)] <- NA ## where is the first value >= 20 ? which.max(x >= 20) ## Also works for lists (which can be coerced to numeric vectors): which.min(list(A = 7, pi = pi)) ## -> c(pi = 2L)