man/examples/getAllItems.R

In EdSurvey: Analysis of NCES Education Survey and Assessment Data

\dontrun{
  #TIMSS Example
  t15 <- readTIMSS(path="~/TIMSS/2015", "usa", 4)
  
  showPlausibleValues(data=t15) #view constructs in console
  
  #ensure we have all data needed for mml.sdf on light.edsurvey.data.frame
  #must be specified ahead of time.  the 'getAllItems' function makes this easy
  mathItems <- getAllItems(sdf=t15, construct="mmat") #get mathematics items
  sciItems <- getAllItems(sdf=t15, construct="ssci") #get science items
  allItems <- getAllItems(sdf=t15, construct="NULL")
  
  wgtVar <- "totwgt"
  psustr <- c(getPSUVar(t15, wgtVar), getStratumVar(t15, wgtVar))
  lsdf <- getData(data=t15,
                  varnames=c("ROWID", "mmat", mathItems, psustr, wgtVar),
                  omittedLevels=FALSE,
                  addAttributes=TRUE) #builds light.edsurvey.data.frame
  
  #as a light.edsurvey.data.frame all elements must be present
  mml.sdf(formula=mmat ~ 1, data=lsdf, weightVar="totwgt")
  
  #as edsurvey.data.frame elements retrieved automatically for user
  mml.sdf(formula=mmat ~ 1, data=t15, weightVar="totwgt") 
  
  #NAEP example
  sdf <- readNAEP(path=system.file("extdata/data", "M36NT2PM.dat", package="NAEPprimer"))
  
  allItems <- getAllItems(sdf=sdf, construct=NULL)
  algebraItems <- getAllItems(sdf=sdf, construct="algebra")
}