forward_mds: Do forward MDS by numerically minimizing the stress defined...

Description Usage Arguments Value

View source: R/forward_methods.R

Description

Do forward MDS by numerically minimizing the stress defined in forward_cost.

Usage

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forward_mds(high_d, weights, dist.func, thresh = 1e-05, max.iters = 1000,
  n.inits = 10, seed = NULL, std = TRUE, symm = FALSE)

Arguments

high_d

The high dimensional data of which a low dimensional representation is desired, an n by p matrix where rows represent observations

dist.func

The distance function to be used for high D distance computation; euclidean is always used for low D distance.

thresh

The threshold below which stress must fall before computation ends.

max.iters

The maximum number of iterations passed to optim for stress minimization.

n.inits

The number of times the optim is run from a random configuration. This can be important, as the cost surface is highly nonconvex.

seed

Random seed used for initialization

std

Boolean, should stress be standardized? This is accomplished by dividing stress by the sum of squared high D distance

symm

Boolean, is the distance function symmetric? We can save on computation if so.

low_d

The low_d solution, an n by 2 matrix, the cost of which is to be evaluated.

Value

List with $par, the optimal configuration as an n by 2 matrix, and $value as the stress of this configuration


NathanWycoff/mds.methods documentation built on May 23, 2019, 7:32 a.m.