ArgMax operation or ArgMax reduction

ArgMax operation or ArgMax reduction for LazyTensor objects.

Usage

argmax(x, index = NA)

argmax_reduction(x, index)

Arguments

x: a LazyTensor or a ComplexLazyTensor.
index: a character corresponding to the wanted reduction dimension, either "i" or "j", to specify whether if the argmax reduction is done along the index i or j. It can be NA (default) when no reduction is desired.

Value

a LazyTensor if index = NA or an array storing the result of the specified argmax reduction otherwise.

Details

If x is a LazyTensor, argmax(x, index) will :

if index = "i", return the argmax reduction of x over the i indexes.
if index = "j", return the argmax reduction of x over the j indexes.
if index = NA (default), return a new LazyTensor object representing the symbolic argmax of the values along the inner dimension of x.

Note: Run browseVignettes("rkeops") to access the vignettes and find details about this function in the "RKeOps LazyTensor" vignette, at section "Reductions".

Note: index input argument cannot be NA for the argmax_reduction() function.

Author

Chloe Serre-Combe, Amelie Vernay

Examples

if (FALSE) {
x <- matrix(runif(150 * 3), 150, 3) # arbitrary R matrix, 150 rows, 3 columns
x_i <- LazyTensor(x, index = 'i')   # creating LazyTensor from matrix x, 
                                    # indexed by 'i'

argmax_xi <- argmax(x_i, "i")  # argmax reduction indexed by 'i'
argmax_x <- argmax(x_i)        # symbolic matrix
}
if (FALSE) {
x <- matrix(runif(150 * 3), 150, 3) # arbitrary R matrix, 150 rows, 3 columns
x_i <- LazyTensor(x, index = 'i')   # creating LazyTensor from matrix x, 
                                    # indexed by 'i'

argmax_red <- argmax_reduction(x_i, "i")  # argmax reduction indexed by 'i'
}