MDP2 (version 2.1.2)

hmpMDPWriter: Function for writing an HMDP model to a hmp file (XML). The function define sub-functions which can be used to define an HMDP model stored in a hmp file.

Description

HMP files are in XML format and human readable using e.g. a text editor. HMP files are not suitable for storing large HMDP models since text files are very verbose. Moreover, approximation of the weights and probabilities may occur since the parser writing the hmp file may no output all digits. If you consider large models then use the binary file format instead.

Usage

hmpMDPWriter(
  file = "r.hmp",
  rate = 0.1,
  rateBase = 1,
  precision = 1e-05,
  desc = "HMP file created using hmpMDPWriter in R",
  getLog = TRUE
)

Value

A list of functions.

Arguments

file

The name of the file storing the model (e.g. r.hmp).

rate

The interest rate (used if consider discounting).

rateBase

The time where the rate is taken over, e.g. if the rate is 0.1 and rateBase is 365 days then we have an interest rate of 10 percent over the year.

precision

The precision used when checking if probabilities sum to one.

desc

Description of the model.

getLog

Output log text.

Details

The functions which can be used are:

• setWeights(labels, duration): Set the labels of the weights used in the actions. labels is a vector of label names, duration A number defining which label that corresponds to duration/time, e.g. if the first entry in labels is time then duration = 1. The function must be called before starting building the model.

• process(): Starts a (sub)process.

• endProcess(): Ends a (sub)process.

• stage(label=NULL): Starts a stage.

• endStage(): Ends a (sub)process.

• state(label=NULL): Starts a state. Returns the states index number sIdx.

• endState(): Ends a stage.

• action(label=NULL, weights, prob, statesNext=NULL): Starts an action. Parameter weights must be a vector of action weights, prob must contain triples of (scope, idx, pr). The scope can be 3 values: * 0: A transition to the next stage in the father process, * 1: A transition to next stage in the current process, * 2: A transition to a child process (stage zero in the child process). idx in the pair denote the index of the state at the stage considered, e.g. if scope = 1 and idx = 2 we consider state number 3 at next stage in the current process (number from zero). Note scope = 3 is not supported in the hmp file format! statesNext is the number of states in the next stage of the process (only needed if have a transition to the father).

• endAction(): Ends an action.

• closeWriter(): Close the writer. Must be called when the model description has finished.

Examples

## Use temp dir
wd <- setwd(tempdir())

## Create a small HMDP with two levels
w<-hmpMDPWriter()
w$setWeights(c("Duration","Net reward","Items"), duration=1)
w$process()
  w$stage()
   w$state(label="M0")
     w$action(label="A0",weights=c(0,0,0),prob=c(2,0,1))
      w$process()
        w$stage()
         w$state(label="D")
           w$action(label="A0",weights=c(0,0,1),prob=c(1,0,0.5,1,1,0.5))
           w$endAction()
         w$endState()
        w$endStage()
        w$stage()
         w$state(label="C0")
           w$action(label="A0",weights=c(0,0,0),prob=c(1,0,1))
           w$endAction()
           w$action(label="A1",weights=c(1,2,1),prob=c(1,0,0.5,1,1,0.5))
           w$endAction()
         w$endState()
         w$state(label="C1")
           w$action(label="A0",weights=c(0,0,0),prob=c(1,0,1))
           w$endAction()
           w$action(label="A1",weights=c(1,2,1),prob=c(1,0,0.5,1,1,0.5))
           w$endAction()
         w$endState()
        w$endStage()
        w$stage()
         w$state(label="C0")
           w$action(label="A0",weights=c(1,4,0),prob=c(0,0,1), statesNext=0)
           w$endAction()
         w$endState()
         w$state(label="C1")
           w$action(label="A0",weights=c(1,4,0),prob=c(0,0,1), statesNext=0)
           w$endAction()
         w$endState()
        w$endStage()
      w$endProcess()
     w$endAction()
     w$action(label="A1",weights=c(0,0,0),prob=c(2,0,1))
      w$process()
        w$stage()
         w$state(label="D")
           w$action(label="A0",weights=c(0,0,1),prob=c(1,0,1))
           w$endAction()
         w$endState()
        w$endStage()
        w$stage()
         w$state(label="C0")
           w$action(label="A0",weights=c(0,0,0),prob=c(1,0,1))
           w$endAction()
           w$action(label="A1",weights=c(1,2,1),prob=c(1,0,0.5,1,1,0.5))
           w$endAction()
         w$endState()
        w$endStage()
        w$stage()
         w$state(label="C0")
           w$action(label="A0",weights=c(1,4,0),prob=c(0,0,1), statesNext=0)
           w$endAction()
         w$endState()
         w$state(label="C1")
           w$action(label="A0",weights=c(1,4,0),prob=c(0,0,1), statesNext=0)
           w$endAction()
           w$action(label="A1",weights=c(0,10,5),prob=c(0,0,0.5,0,1,0.5), statesNext=0)
           w$endAction()
         w$endState()
        w$endStage()
      w$endProcess()
     w$endAction()
   w$endState()
   w$state(label="M1")
     w$action(label="A0",weights=c(0,0,0),prob=c(2,0,1))
      w$process()
        w$stage()
         w$state(label="D")
           w$action(label="A0",weights=c(0,0,1),prob=c(1,0,0.5,1,1,0.5))
           w$endAction()
         w$endState()
        w$endStage()
        w$stage()
         w$state(label="C0")
           w$action(label="A0",weights=c(0,0,0),prob=c(1,0,1))
           w$endAction()
         w$endState()
         w$state(label="C1")
           w$action(label="A0",weights=c(0,0,0),prob=c(1,0,1))
           w$endAction()
         w$endState()
        w$endStage()
        w$stage()
         w$state(label="C0")
           w$action(label="A0",weights=c(1,4,0),prob=c(0,0,1), statesNext=0)
           w$endAction()
         w$endState()
         w$state(label="C1")
           w$action(label="A0",weights=c(1,4,0),prob=c(0,0,1), statesNext=0)
           w$endAction()
         w$endState()
        w$endStage()
      w$endProcess()
     w$endAction()
   w$endState()
  w$endStage()
w$endProcess()
w$closeWriter()

## Have a look at the hmp file
cat(readr::read_file("r.hmp"))

## Reset working dir
setwd(wd)