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lqmix (version 1.2)

lqr: Linear Quantile Regression

Description

Estimate a linear quantile regression model for independent data (no random coefficients).

Usage

lqr(formula, data, qtl = 0.5, se = TRUE, R = 100, verbose = TRUE,
  seed = NULL, parallel = FALSE, ncores = 2, ...)

Value

Return an object of class

lqr. This is a list containing the following elements:

betaf

a vector containing fixed regression coefficients

scale

the scale parameter

sigma.e

the standard deviation of error terms

lk

the log-likelihood

npar

the total number of model parameters

AIC

the AIC value

BIC

the BIC value

qtl

the estimated quantile

nobs

the total number of observations

se.betaf

the standard errors for the regression coefficients

se.scale

the standard error for the scale parameter

model

the estimated model

mmf

the model matrix associated to the regression coefficients

y

the model response

call

the matched call

formula

the model formula

Arguments

formula

an object of class formula: a symbolic description of the model to be fitted

data

a data frame containing the variables named in formula

qtl

quantile to be estimated

se

standard error computation

R

number of bootstrap samples for computing standard errors

verbose

if set to FALSE, no printed output is given during the function execution

seed

an integer value for random numbers generation, used for bootstrap standard errors

parallel

if set to TRUE, a parallelized code is use for standard error computation (if se=TRUE)

ncores

number of cores used for computing bootstrap standard errors (if required)

...

not used

Details

The function computes ML estimates for the parameters of a linear quantile regression model for independent observations. Estimates are derived by maximizing the (log-)likelihood of a Laplace regression, where the location parameter is modeled as a function of fixed coefficients only.

If se=TRUE, standard errors based on a bootstrap procedure are computed.

References

ref:KoeBaslqmix

Examples

Run this code
out0 = lqr(formula=meas~trt+time+trt:time,data=pain,se=TRUE,R=10)

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