bootstrap_sd_sl: Bootstrap standard deviation for the slope of a psychometric...

In modelfree: Model-Free Estimation of a Psychometric Function

Bootstrap standard deviation for the slope of a psychometric function

Description

The function finds a bootstrap estimate of the standard deviation of the estimated slope for the local polynomial estimate of the psychometric function with guessing and lapsing rates.

Usage

bootstrap_sd_sl( TH, r, m, x, N, h0, X = (max(x)-min(x))*(0:999)/999+min(x),
                 link = "logit", guessing = 0, lapsing = 0, K = 2, p = 1,
                 ker = "dnorm", maxiter = 50, tol = 1e-6 )

Arguments

TH	required threshold level
r	number of successes at points x
m	number of trials at points x
x	stimulus levels
N	number of bootstrap replications; N should be at least 200 for reliable results
h0	bandwidth
X	(optional) set of values at which estimates of the psychometric function for the slope estimation are to be obtained; if not given, 1000 equally spaced points from minimum to maximum of x are used
link	(optional) name of the link function; default is "logit"
guessing	(optional) guessing rate; default is 0
lapsing	(optional) lapsing rate; default is 0
K	(optional) power parameter for Weibull and reverse Weibull link; default is 2
p	(optional) degree of the polynomial; default is 1
ker	(optional) kernel function for weights; default is "dnorm"
maxiter	(optional) maximum number of iterations in Fisher scoring; default is 50
tol	(optional) tolerance level at which to stop Fisher scoring; default is 1e-6

Value

⁠sd ⁠ bootstrap estimate of the standard deviation of the slope estimator

⁠sl0 ⁠ slope estimate

Examples

## Not run: 
data("Miranda_Henson")
x = Miranda_Henson$x
r = Miranda_Henson$r
m = Miranda_Henson$m
bwd_min <- min( diff( x ) )
bwd_max <- max( x ) - min( x )
bwd <- bandwidth_cross_validation( r, m, x, c( bwd_min, bwd_max ), method = "deviance" )
prob <- 0.5 # Required threshold level
# This might take a few minutes
niter <- 200 # Note number of bootstrap iterations should be at least 200
sd_sl <- bootstrap_sd_sl( prob, r, m, x, niter, bwd ) # Be patient, slow process

## End(Not run)

modelfree documentation built on May 31, 2023, 7:17 p.m.