sirt (version 3.0-32)

sirt-utilities: Utility Functions in sirt

Description

Utility functions in sirt.

Usage

# bounds entries in a vector
bounds_parameters( pars, lower=NULL, upper=NULL)
# improper density function which always returns a value of 1
dimproper(x)
# generalized inverse of a symmetric function
ginverse_sym(A, eps=1E-8)
# hard thresholding function
hard_thresholding(x, lambda)
# soft thresholding function
soft_thresholding(x, lambda)
# power function x^a, like in Cpp
pow(x, a)
# trace of a matrix
tracemat(A)
# plyr::rbind.fill implementation in sirt
sirt_rbind_fill(x, y)
# Fisher-z transformation, see psych::fisherz
sirt_fisherz(rho)
# inverse Fisher-z transformation, see psych::fisherz2r
sirt_antifisherz(z)
# attach all elements in a list in a specified environment
sirt_attach_list_elements(x, envir)
# switch between stats::optim and stats::nlminb
sirt_optimizer(optimizer, par, fn, grad=NULL, method="L-BFGS-B", ...)
# print objects in a summary
sirt_summary_print_objects(obji, from=NULL, to=NULL, digits=3, rownames_null=TRUE)
# print package version and R session
sirt_summary_print_package_rsession(pack)
# print package version
sirt_summary_print_package(pack)
# print R session
sirt_summary_print_rsession()
# print call
sirt_summary_print_call(CALL)

Arguments

pars

Numeric vector

lower

Numeric vector

upper

Numeric vector

x

Numeric vector or a matrix or a list

eps

Numerical. Shrinkage parameter of eigenvalue in ginverse_sym

a

Numeric vector

lambda

Numeric value

A

Matrix

y

Matrix

rho

Numeric

z

Numeric

envir

Environment

optimizer

Can be optim or nlminb

par

Initial parameter

fn

Function

grad

Gradient

method

Optimization method

…

Further arguments to be passed

obji

Data frame

from

Integer

to

Integer

digits

Integer

rownames_null

Logical

pack

Package name

CALL

Call statement

Examples

# NOT RUN {
#############################################################################
## EXAMPLE 1: Trace of a matrix
#############################################################################

set.seed(86)
A <- matrix( stats::runif(4), 2,2 )
tracemat(A)
sum(diag(A))    #=sirt::tracemat(A)

#############################################################################
## EXAMPLE 2: Power function
#############################################################################

x <- 2.3
a <- 1.7
pow(x=x,a=a)
x^a            #=sirt::pow(x,a)

#############################################################################
## EXAMPLE 3: Soft and hard thresholding function (e.g. in LASSO estimation)
#############################################################################

x <- seq( -2, 2, length=100 )
y <- sirt::soft_thresholding( x, lambda=.5)
graphics::plot( x, y, type="l")

z <- sirt::hard_thresholding( x, lambda=.5)
graphics::lines( x, z, lty=2, col=2)

#############################################################################
## EXAMPLE 4: Bounds on parameters
#############################################################################

pars <- c( .721, .346 )
bounds_parameters( pars=pars, lower=c(-Inf, .5), upper=c(Inf,1) )
# }