#' Influential species detection - Phylogenetic Logistic Regression
#'
#' Performs leave-one-out deletion analysis for phylogenetic logistic regression,
#' and detects influential species.
#'
#' @param formula The model formula
#' @param data Data frame containing species traits with row names matching tips
#' in \code{phy}.
#' @param phy A phylogeny (class 'phylo') matching \code{data}.
#' @param btol Bound on searching space. For details see \code{phyloglm}
#' @param cutoff The cutoff value used to identify for influential species
#' (see Details)
#' @param track Print a report tracking function progress (default = TRUE)
#' @param ... Further arguments to be passed to \code{phyloglm}
#' @details
#' This function sequentially removes one species at a time, fits a phylogenetic
#' logistic regression model using \code{\link[phylolm]{phyloglm}}, stores the
#' results and detects influential species.
#'
#' Currently only logistic regression using the "logistic_MPLE"-method from
#' \code{phyloglm} is implemented.
#'
#' \code{influ_phyglm} detects influential species based on the standardised
#' difference in intercept and/or slope when removing a given species compared
#' to the full model including all species. Species with a standardised difference
#' above the value of \code{cutoff} are identified as influential. The default
#' value for the cutoff is 2 standardised differences change.
#'
#' Currently, this function can only implement simple logistic models (i.e. \eqn{trait~
#' predictor}). In the future we will implement more complex models.
#'
#' Output can be visualised using \code{sensi_plot}.
#'
#' @return The function \code{influ_phyglm} returns a list with the following
#' components:
#' @return \code{cutoff}: The value selected for \code{cutoff}
#' @return \code{formula}: The formula
#' @return \code{full.model.estimates}: Coefficients, aic and the optimised
#' value of the phylogenetic parameter (i.e. \code{alpha}) for the full model
#' without deleted species.
#' @return \code{influential_species}: List of influential species, both
#' based on standardised difference in intercept and in the slope of the
#' regression. Species are ordered from most influential to less influential and
#' only include species with a standardised difference > \code{cutoff}.
#' @return \code{sensi.estimates}: A data frame with all simulation
#' estimates. Each row represents a deleted clade. Columns report the calculated
#' regression intercept (\code{intercept}), difference between simulation
#' intercept and full model intercept (\code{DIFintercept}), the standardised
#' difference (\code{sDIFintercept}), the percentage of change in intercept compared
#' to the full model (\code{intercept.perc}) and intercept p-value
#' (\code{pval.intercept}). All these parameters are also reported for the regression
#' slope (\code{DIFestimate} etc.). Additionally, model aic value (\code{AIC}) and
#' the optimised value (\code{optpar}) of the phylogenetic parameter
#' (i.e. \code{alpha}) are reported.
#' @return \code{data}: Original full dataset.
#' @return \code{errors}: Species where deletion resulted in errors.
#' @author Gustavo Paterno & Gijsbert D.A. Werner
#' @seealso \code{\link[phylolm]{phyloglm}}, \code{\link{samp_phyglm}},
#' \code{\link{influ_phylm}}, \code{\link{sensi_plot}}
#' @references
#'
#' Paterno, G. B., Penone, C. Werner, G. D. A.
#' \href{http://doi.wiley.com/10.1111/2041-210X.12990}{sensiPhy:
#' An r-package for sensitivity analysis in phylogenetic
#' comparative methods.} Methods in Ecology and Evolution
#' 2018, 9(6):1461-1467.
#'
#' Ho, L. S. T. and Ane, C. 2014. "A linear-time algorithm for
#' Gaussian and non-Gaussian trait evolution models". Systematic Biology 63(3):397-408.
#' @examples
#'# Simulate Data:
#'set.seed(6987)
#'phy = rtree(100)
#'x = rTrait(n=1,phy=phy)
#'X = cbind(rep(1,100),x)
#'y = rbinTrait(n=1,phy=phy, beta=c(-1,0.5), alpha=.7 ,X=X)
#'dat = data.frame(y, x)
#'# Run sensitivity analysis:
#'influ <- influ_phyglm(y ~ x, data = dat, phy = phy)
#'# To check summary results and most influential species:
#'summary(influ)
#'# Visual diagnostics for clade removal:
#'sensi_plot(influ)
#' @export
influ_phyglm <- function(formula,
data,
phy,
btol = 50,
cutoff = 2,
track = TRUE,
...) {
if (!inherits(formula, "formula"))
stop("formula must be class 'formula'")
if (!inherits(data, "data.frame"))
stop("data must be class 'data.frame'")
if (!inherits(phy, "phylo"))
stop("phy must be class 'phylo'")
else
# Check match between data and phy
data_phy <-
match_dataphy(formula, data, phy, ...)
#Calculates the full model, extracts model parameters
full.data <- data_phy$data
phy <- data_phy$phy
#Calculates the full model, extracts model parameters
N <- nrow(full.data)
mod.0 <-
phylolm::phyloglm(
formula,
data = full.data,
phy = phy,
method = "logistic_MPLE",
btol = btol
)
intercept.0 <- mod.0$coefficients[[1]]
estimate.0 <- mod.0$coefficients[[2]]
pval.intercept.0 <-
phylolm::summary.phyloglm(mod.0)$coefficients[[1, 4]]
pval.estimate.0 <-
phylolm::summary.phyloglm(mod.0)$coefficients[[2, 4]]
optpar.0 <- mod.0$alpha
if (isTRUE(mod.0$convergence != 0))
stop("Full model failed to converge,
consider changing btol. See ?phyloglm")
else
#Creates empty data frame to store model outputs
sensi.estimates <-
data.frame(
"species" = numeric(),
"intercept" = numeric(),
"DIFintercept" = numeric(),
"intercept.perc" = numeric(),
"pval.intercept" = numeric(),
"estimate" = numeric(),
"DIFestimate" = numeric(),
"estimate.perc" = numeric(),
"pval.estimate" = numeric(),
"AIC" = numeric(),
"optpar" = numeric()
)
#Loops over all species, and removes each one individually
counter <- 1
errors <- NULL
if (track == TRUE)
pb <- utils::txtProgressBar(min = 0,
max = N,
style = 3)
for (i in 1:N) {
crop.data <- full.data[c(1:N)[-i],]
crop.phy <-
ape::drop.tip(phy, phy$tip.label[i])
mod = try(phylolm::phyloglm(
formula,
data = crop.data,
phy = crop.phy,
method = "logistic_MPLE",
btol = btol
),
TRUE)
if (isTRUE(class(mod) == "try-error")) {
error <- i
names(error) <-
rownames(full.data$data)[i]
errors <- c(errors, error)
next
}
else {
sp <- phy$tip.label[i]
intercept <-
mod$coefficients[[1]]
estimate <-
mod$coefficients[[2]]
DIFintercept <-
intercept - intercept.0
DIFestimate <-
estimate - estimate.0
intercept.perc <-
round((abs(DIFintercept / intercept.0)) * 100, digits = 1)
estimate.perc <-
round((abs(DIFestimate / estimate.0)) * 100, digits = 1)
pval.intercept <-
phylolm::summary.phyloglm(mod)$coefficients[[1, 4]]
pval.estimate <-
phylolm::summary.phyloglm(mod)$coefficients[[2, 4]]
aic.mod <- mod$aic
optpar <- mod$alpha
if (track == TRUE)
utils::setTxtProgressBar(pb, i)
#Stores values for eacht simulation
estim.simu <-
data.frame(
sp,
intercept,
DIFintercept,
intercept.perc,
pval.intercept,
estimate,
DIFestimate,
estimate.perc,
pval.estimate,
aic.mod,
optpar,
stringsAsFactors = F
)
sensi.estimates[counter, ] <-
estim.simu
counter = counter + 1
}
}
if (track == TRUE)
on.exit(close(pb))
#Calculates standardized DFbeta and DIFintercept
sDIFintercept <- sensi.estimates$DIFintercept /
stats::sd(sensi.estimates$DIFintercept)
sDIFestimate <- sensi.estimates$DIFestimate /
stats::sd(sensi.estimates$DIFestimate)
sensi.estimates$sDIFestimate <- sDIFestimate
sensi.estimates$sDIFintercept <- sDIFintercept
#Creates a list with full model estimates:
param0 <-
list(
coef = phylolm::summary.phyloglm(mod.0)$coefficients,
aic = phylolm::summary.phyloglm(mod.0)$aic,
optpar = phylolm::summary.phyloglm(mod.0)$alpha
)
#Identifies influencital species (sDF > cutoff) and orders by influence
reorder.on.estimate <-
sensi.estimates[order(abs(sensi.estimates$sDIFestimate), decreasing =
T), c("species", "sDIFestimate")]
influ.sp.estimate <-
as.character(reorder.on.estimate$species[abs(reorder.on.estimate$sDIFestimate) >
cutoff])
reorder.on.intercept <-
sensi.estimates[order(abs(sensi.estimates$sDIFintercept), decreasing =
T), c("species", "sDIFintercept")]
influ.sp.intercept <-
as.character(reorder.on.intercept$species[abs(reorder.on.intercept$sDIFintercept) >
cutoff])
#Generates output:
res <- list(
cutoff = cutoff,
formula = formula,
full.model.estimates = param0,
influential.species = list(
influ.sp.estimate = influ.sp.estimate,
influ.sp.intercept = influ.sp.intercept
),
sensi.estimates = sensi.estimates,
data = full.data,
errors = errors
)
class(res) <- "sensiInflu"
### Warnings:
if (length(res$errors) > 0) {
warning("Some species deletion presented errors, please check: output$errors")
}
else {
res$errors <- "No errors found."
}
return(res)
}
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