LogSumExp-class function

The LogSumExp class.

The natural logarithm of the sum of the elementwise exponential, $\log\sum_{i=1}^n e^{x_i}$. class

LogSumExp(x, axis = NA_real_, keepdims = FALSE)

## S4 method for signature 'LogSumExp'
to_numeric(object, values)

## S4 method for signature 'LogSumExp'
.grad(object, values)

## S4 method for signature 'LogSumExp'
.column_grad(object, value)

## S4 method for signature 'LogSumExp'
sign_from_args(object)

## S4 method for signature 'LogSumExp'
is_atom_convex(object)

## S4 method for signature 'LogSumExp'
is_atom_concave(object)

## S4 method for signature 'LogSumExp'
is_incr(object, idx)

## S4 method for signature 'LogSumExp'
is_decr(object, idx)

Arguments

• x: An Expression representing a vector or matrix.
• axis: (Optional) The dimension across which to apply the function: 1 indicates rows, 2 indicates columns, and NA indicates rows and columns. The default is NA.
• keepdims: (Optional) Should dimensions be maintained when applying the atom along an axis? If FALSE, result will be collapsed into an $n x 1$ column vector. The default is FALSE.
• object: A LogSumExp object.
• values: A list of numeric values.
• value: A numeric value.
• idx: An index into the atom.

Methods (by generic)

• to_numeric(LogSumExp): Evaluates $e^x$ elementwise, sums, and takes the natural log.
• .grad(LogSumExp): Gives the (sub/super)gradient of the atom w.r.t. each variable
• .column_grad(LogSumExp): Gives the (sub/super)gradient of the atom w.r.t. each column variable.
• sign_from_args(LogSumExp): Returns sign (is positive, is negative) of the atom.
• is_atom_convex(LogSumExp): The atom is convex.
• is_atom_concave(LogSumExp): The atom is not concave.
• is_incr(LogSumExp): The atom is weakly increasing in the index.
• is_decr(LogSumExp): The atom is not weakly decreasing in the index.

Slots

• x: An Expression representing a vector or matrix.
• axis: (Optional) The dimension across which to apply the function: 1 indicates rows, 2 indicates columns, and NA indicates rows and columns. The default is NA.
• keepdims: (Optional) Should dimensions be maintained when applying the atom along an axis? If FALSE, result will be collapsed into an $n x 1$ column vector. The default is FALSE.