which.min
Where is the Min() or Max() or first TRUE or FALSE ?
Description
Determines the location, i.e., index of the (first) minimum or maximum of a numeric (or logical) vector.
Usage
which.min(x) which.max(x)
Arguments
x | numeric (logical, integer or double) vector or an R object for which the internal coercion to |
Value
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.
Logical x
– First TRUE
or FALSE
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
. However, match(FALSE, x)
or match(TRUE, x)
are typically preferred, as they do indicate mismatches.
Author(s)
Martin Maechler
See Also
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).
Examples
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)
Copyright (©) 1999–2012 R Foundation for Statistical Computing.
Licensed under the GNU General Public License.