Interactive Q-Learning
The complete interactive Q-Learning algorithm.
## Second-Stage Analysis
iqLearnSS(..., moMain, moCont, data, response, txName, iter = 0L, 
          verbose = TRUE)
## First-Stage Analysis for Fitted Main Effects
iqLearnFSM(..., moMain, moCont, data, response, txName, iter = 0L, 
           verbose = TRUE)
## First-Stage Analysis for Fitted Contrasts
iqLearnFSC(..., moMain, moCont, data, response, txName, iter = 0L, 
           verbose = TRUE)
## First-Stage Analysis of Contrast Variance Log-Linear Model
iqLearnFSV(..., object, moMain, moCont, data, iter = 0L, verbose = TRUE)... | 
 ignored. Provided to require named inputs.  | 
moMain | 
 An object of class modelObj or a list of objects of class modelObjSubset, which define the models and R methods to be used to obtain parameter estimates and predictions for the main effects component of the outcome regression. See ?modelObj and/or ?modelObjSubset for details. NULL is an acceptable value if moCont is defined.  | 
moCont | 
 An object of class modelObj or a list of objects of class modelObjSubset, which define the models and R methods to be used to obtain parameter estimates and predictions for the contrasts component of the outcome regression. See ?modelObj and/or ?modelObjSubset for details. NULL is an acceptable value if moMain is defined.  | 
data | 
 A data frame of covariates and treatment history.  | 
response | 
 For the second stage analysis, the response vector. For first stage analyses, the value object returned by iqLearnSS().  | 
object | 
 The value object returned by iqLearFSC()  | 
txName | 
 A character string giving column header of treatment variable in data  | 
iter | 
 An integer. See ?iter for details  | 
verbose | 
 A logical. If TRUE, screen prints are generated.  | 
Laber, EB, Linn, KA, and Stefanski, LA (2014). Interactive model building for Q-Learning. Biometrika, 101, 831–847. PMCID: PMC4274394.
Other statistical methods: 
bowl(),
earl(),
optimalClass(),
optimalSeq(),
owl(),
qLearn(),
rwl()
Other multiple decision point methods: 
bowl(),
optimalClass(),
optimalSeq(),
qLearn()
# Load and process data set
data(bmiData)
# define the negative 12 month change in BMI from baseline
y12 <- -100*(bmiData[,6L] - bmiData[,4L])/bmiData[,4L]
#### Full Interactive Q-Learning Algorithm
### Second-Stage Analysis
# outcome model
moMain <- buildModelObj(model = ~parentBMI+month4BMI,
                        solver.method = 'lm')
moCont <- buildModelObj(model = ~race + parentBMI+month4BMI,
                        solver.method = 'lm')
fitSS <- iqLearnSS(moMain = moMain, moCont = moCont,
                   data = bmiData, response = y12,  txName = 'A2')
### First-Stage Analysis Main Effects Term
# main effects model
moMain <- buildModelObj(model = ~parentBMI+baselineBMI,
                        solver.method = 'lm')
moCont <- buildModelObj(model = ~race + parentBMI+baselineBMI,
                        solver.method = 'lm')
fitFSM <- iqLearnFSM(moMain = moMain, moCont = moCont,
                     data = bmiData, response = fitSS,  txName = 'A1')
### First-Stage Analysis Contrasts Term
# contrasts model
moMain <- buildModelObj(model = ~parentBMI+baselineBMI,
                        solver.method = 'lm')
moCont <- buildModelObj(model = ~race + parentBMI+baselineBMI,
                        solver.method = 'lm')
fitFSC <- iqLearnFSC(moMain = moMain, moCont = moCont,
                     data = bmiData, response = fitSS,  txName = 'A1')
### First-Stage Analysis Contrasts Variance - Log-linear
# contrasts variance model
moMain <- buildModelObj(model = ~baselineBMI,
                        solver.method = 'lm')
moCont <- buildModelObj(model = ~baselineBMI,
                        solver.method = 'lm')
fitFSV <- iqLearnFSV(object = fitFSC, moMain = moMain, moCont = moCont,
                     data = bmiData)
####Available methods
  ### Estimated value
  estimator(x = fitFSC, y = fitFSM, z = fitFSV, w = fitSS, dens = 'nonpar')
  ## Estimated optimal treatment and decision functions for training data
  ## Second stage optimal treatments
  optTx(x = fitSS)
  ## First stage optimal treatments when contrast variance is modeled.
  optTx(x = fitFSM, y = fitFSC, z = fitFSV, dens = 'nonpar')
  ## First stage optimal treatments when contrast variance is constant.
  optTx(x = fitFSM, y = fitFSC, dens = 'nonpar')
  ## Estimated optimal treatment and decision functions for new data
  ## Second stage optimal treatments
  optTx(x = fitSS, bmiData)
  ## First stage optimal treatments when contrast variance is modeled.
  optTx(x = fitFSM, y = fitFSC, z = fitFSV, dens = 'nonpar', bmiData)
  ## First stage optimal treatments when contrast variance is constant.
  optTx(x = fitFSM, y = fitFSC, dens = 'nonpar', bmiData)
### The following methods are available for all objects: fitSS, fitFSM,
### fitFSC and fitFSV. We include only one here for illustration.
  # Coefficients of the outcome regression objects
  coef(object = fitSS)
  # Description of method used to obtain object
  DTRstep(object = fitFSM)
  # Value object returned by outcome regression method
  fitObject(object = fitFSC)
  # Value object returned by outcome regression method
  outcome(object = fitFSV)
  # Plots if defined by outcome regression method
  dev.new()
  par(mfrow = c(2,4))
  plot(x = fitSS)
  plot(x = fitSS, suppress = TRUE)
  # Show main results of method
  show(object = fitFSM)
  # Show summary results of method
  summary(object = fitFSV)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.