residuals.lod_lm {lodr}

Extract lod_lm residuals

Description

Extracts residuals from object of class "lod_lm".

Usage

## S3 method for class 'lod_lm'
residuals(object, ...)

Arguments

object

An object of class "lod_lm", usually, a result of a call to lod_lm

...

further arguments passed to or from other methods.

Details

For subjects with covariates outside of limits of detection, when computing residuals the values for these covariates are set according to method specified by argument fill_in_method in call to lod_lm.

Value

Residuals extracted from object as a named numeric vector.

Author(s)

Kevin Donovan, [e-mail].

Maintainer: Kevin Donovan <[e-mail]>

References

May RC, Ibrahim JG, Chu H (2011). “Maximum likelihood estimation in generalized linear models with multiple covariates subject to detection limits.” Statistics in medicine, 30(20), 2551–2561.

See Also

fitted.lod_lm and coef.lod_lm for related methods; lod_lm for model fitting.

The generic functions coef and fitted.

Examples

library(lodr)
## Using example dataset provided in lodr package: lod_data_ex
## 3 covariates: x1, x2, x3 with x2 and x3 subject to a lower limit of
## detection of 0

## nSamples set to 100 for computational speed/illustration purposes only.  
## At least 250 is recommended.  Same for boots=0; results in NAs returned for standard errors

fit <- lod_lm(data=lod_data_ex, frmla=y~x1+x2+x3, lod=c(0,0),
                  var_LOD=c("x2", "x3"), nSamples=100, boots=0)
 residuals(fit)