plot.iqResids: Plot the standardized residuals

In iqLearn: Interactive Q-Learning

Description

Plot the standardized residuals that arise from the contrast function mean and variance modeling.

Usage

## S3 method for class 'iqResids'
plot(x, ...)

Arguments

x	object of type iqResids
...	additional arguments to be passed to plot()

Details

Can be used to decide which density estimator ("norm" or "nonpar") should be used for the conditional density of the contrast function given first-stage history and treatment.

Value

Returns a normal QQ-plot of the standardized residuals.

Author(s)

Kristin A. Linn <[e-mail]>, Eric B. Laber, Leonard A. Stefanski

References

Linn, K. A., Laber, E. B., Stefanski, L. A. (2015) "iqLearn: Interactive Q-Learning in R", Journal of Statistical Software, 64(1), 1–25.

Laber, E. B., Linn, K. A., and Stefanski, L. A. (2014) "Interactive model building for Q-learning", Biometrika, 101(4), 831-847.

See Also

iqResids

Examples

## load in two-stage BMI data
data (bmiData)
bmiData$A1[which (bmiData$A1=="MR")] = 1
bmiData$A1[which (bmiData$A1=="CD")] = -1
bmiData$A2[which (bmiData$A2=="MR")] = 1
bmiData$A2[which (bmiData$A2=="CD")] = -1
bmiData$A1 = as.numeric (bmiData$A1)
bmiData$A2 = as.numeric (bmiData$A2)
s1vars = bmiData[,1:4]
s2vars = bmiData[,c (1, 3, 5)]
a1 = bmiData[,7]
a2 = bmiData[,8]
## define response y to be the negative 12 month change in BMI from
## baseline 
y = -(bmiData[,6] - bmiData[,4])/bmiData[,4]
s2ints = c (2, 3)
## second-stage regression
fitIQ2 = learnIQ2 (y ~ gender + parent_BMI + month4_BMI +
  A2*(parent_BMI + month4_BMI), data=bmiData, "A2", c("parent_BMI",
                                  "month4_BMI"))
## model conditional mean of contrast function 
fitIQ1cm = learnIQ1cm (~ gender + race + parent_BMI + baseline_BMI +
	 A1*(gender + parent_BMI + baseline_BMI), data=bmiData, "A1",
	 c ("gender", "parent_BMI", "baseline_BMI"), fitIQ2) 
## variance modeling
fitIQ1var = learnIQ1var (~ gender + race + parent_BMI + baseline_BMI +
  A1*(parent_BMI), data=bmiData, "A1", c ("parent_BMI"), "hetero",
  fitIQ1cm)
## plot standardized residuals
fitResids = iqResids (fitIQ1var)
plot (fitResids)

iqLearn documentation built on May 2, 2019, 6:44 a.m.