The matrix fraction function $$tr(X^T P^{-1} X)$$.

MatrixFrac(X, P)

# S4 method for MatrixFrac
allow_complex(object)

# S4 method for MatrixFrac
to_numeric(object, values)

# S4 method for MatrixFrac
validate_args(object)

# S4 method for MatrixFrac
dim_from_args(object)

# S4 method for MatrixFrac
sign_from_args(object)

# S4 method for MatrixFrac
is_atom_convex(object)

# S4 method for MatrixFrac
is_atom_concave(object)

# S4 method for MatrixFrac
is_incr(object, idx)

# S4 method for MatrixFrac
is_decr(object, idx)

# S4 method for MatrixFrac

# S4 method for MatrixFrac
is_qpwa(object)

# S4 method for MatrixFrac
.domain(object)

# S4 method for MatrixFrac
.grad(object, values)

## Arguments

X

An Expression or numeric matrix.

P

An Expression or numeric matrix.

object

A MatrixFrac object.

values

A list of numeric values for the arguments

idx

An index into the atom.

## Methods (by generic)

• allow_complex(MatrixFrac): Does the atom handle complex numbers?

• to_numeric(MatrixFrac): The trace of $$X^TP^{-1}X$$.

• validate_args(MatrixFrac): Check that the dimensions of x and P match.

• dim_from_args(MatrixFrac): The atom is a scalar.

• sign_from_args(MatrixFrac): The atom is positive.

• is_atom_convex(MatrixFrac): The atom is convex.

• is_atom_concave(MatrixFrac): The atom is not concave.

• is_incr(MatrixFrac): The atom is not monotonic in any argument.

• is_decr(MatrixFrac): The atom is not monotonic in any argument.

• is_quadratic(MatrixFrac): True if x is affine and P is constant.

• is_qpwa(MatrixFrac): True if x is piecewise linear and P is constant.

• .domain(MatrixFrac): Returns constraints describing the domain of the node

• .grad(MatrixFrac): Gives the (sub/super)gradient of the atom w.r.t. each variable

## Slots

X

An Expression or numeric matrix.

P

An Expression or numeric matrix.