tf.switch_case

tf_switch(
branch_index,
...,
branch_fns = list(...),
default = NULL,
name = "switch_case"
)

## Arguments

branch_index an integer tensor a list of function bodies specified with a ~, optionally supplied with a branch index on the left hand side. See examples A function defined with a ~, or something coercible via as.function() a string, passed on to tf.switch_case()

## Value

The result from tf.switch_case()

## Examples

if (FALSE) {
tf_pow <- tf_function(function(x, pow) {
tf_switch(pow,
0 ~ 1,
1 ~ x,
2 ~ x * x,
3 ~ x * x * x,
default = ~ -1)
})

# can optionally also omit the left hand side int, in which case the order of
# the functions is used.
tf_pow <- function(x, pow) {
tf_switch(pow,
~ 1,
~ x,
~ x * x,
~ x * x * x,
default = ~ -1)
}

# supply just some of the ints to override the default order
tf_pow <- function(x, pow) {
tf_switch(pow,
3 ~ x * x * x,
2 ~ x * x,
~ 1,
~ x,
default = ~ -1)
}

# A slightly less contrived example:
tf_norm <- tf_function(function(x, l) {
tf_switch(l,
0 ~ tf$reduce_sum(tf$cast(x != 0, tf$float32)), # L0 norm 1 ~ tf$reduce_sum(tf$abs(x)), # L1 norm 2 ~ tf$sqrt(tf$reduce_sum(tf$square(x))),       # L2 norm
default = ~ tf$reduce_max(tf$abs(x)))         # L-infinity norm
})
}
`