Positive Numbers

The manifold PositiveNumbers represents positive numbers with hyperbolic geometry. Additionally, there are also short forms for its corresponding PowerManifolds, i.e. PositiveVectors, PositiveMatrices, and PositiveArrays.

Manifolds.PositiveNumbersType
PositiveNumbers <: Manifold{ℝ}

The hyperbolic manifold of positive numbers $H^1$ is a the hyperbolic manifold represented by just positive numbers.

Constructor

PositiveNumbers()

Generate the -valued hyperbolic model represented by positive positive numbers. To use this with arrays (1-element arrays), please use SymmetricPositiveDefinite(1).

Base.expMethod
exp(M::PositiveNumbers, p, X)

Compute the exponential map on the PositiveNumbersM.

\[\exp_p X = p\operatorname{exp}(X/p).\]

Base.logMethod
log(M::PositiveNumbers, p, q)

Compute the logarithmic map on the PositiveNumbersM.

\[\log_p q = p\log\frac{q}{p}.\]

ManifoldsBase.check_tangent_vectorMethod
check_tangent_vector(M::PositiveNumbers, p, X; check_base_point, kwargs...)

Check whether X is a tangent vector in the tangent space of p on the PositiveNumbersM. For the real-valued case represented by positive numbers, all X are valid, since the tangent space is the whole real line. For the complex-valued case X [...]

ManifoldsBase.distanceMethod
distance(M::PositiveNumbers, p, q)

Compute the distance on the PositiveNumbersM, which is

\[d(p,q) = \Bigl\lvert \log \frac{p}{q} \Bigr\rvert = \lvert \log p - \log q\rvert.\]

ManifoldsBase.innerMethod
inner(M::PositiveNumbers, p, X, Y)

Compute the inner product of the two tangent vectors X,Y from the tangent plane at p on the PositiveNumbersM, i.e.

\[g_p(X,Y) = \frac{XY}{p^2}.\]

ManifoldsBase.vector_transport_toMethod
vector_transport_to(M::PositiveNumbers, p, X, q, ::ParallelTransport)

Compute the parallel transport of X from the tangent space at p to the tangent space at q on the PositiveNumbersM.

\[\mathcal P_{q\gets p}(X) = X\cdot\frac{q}{p}.\]