phytoclass (version 2.3.1)

Random_neighbour: Select a random neighbour when the previous random neighbour is beyond the minimum or maximum value. Part of the simulated annealing algorithm.

Description

Select a random neighbour when the previous random neighbour is beyond the minimum or maximum value. Part of the simulated annealing algorithm.

Usage

Random_neighbour(f_new, Temp, chlv, N, place, S, S_weights, minF, maxF)

Value

A list containing:

F matrix

The new F matrix with randomly modified values

RMSE

Root mean square error of the new solution

C matrix

The concentration matrix from NNLS

Arguments

f_new

Current F matrix of pigment ratios

Temp

Current temperature in the annealing process

chlv

Chlorophyll-a column to append to the matrix

N

Indices of pigment ratios to be modified

place

Vector of indices where values are non-zero in the F matrix

S

Matrix of samples (rows) and pigments (columns)

S_weights

Vector of weights for each pigment in NNLS

minF

Minimum bounds for each pigment ratio

maxF

Maximum bounds for each pigment ratio

Examples

 # Setup based on simulated_annealing usage
 Fmat <- as.matrix(phytoclass::Fm)
 S <- as.matrix(phytoclass::Sm)
 S_weights <- as.numeric(phytoclass:::Bounded_weights(S))
 place <- which(Fmat[, seq(ncol(Fmat) - 2)] > 0)
 min_max <- phytoclass::min_max
 minF <- min_max[[3]][seq_along(place)]
 maxF <- min_max[[4]][seq_along(place)]
 chlv <- rep(1, nrow(Fmat)) # typical usage in simulated_annealing
 Temp <- 0.5
 N <- place
 # Run Random_neighbour
 result <- phytoclass:::Random_neighbour(Fmat, Temp, chlv, N, place, S, S_weights, minF, maxF)