Question

I would like to have a small function displaying basic data statistics for eachnumeric variable in a given dataset. So far I have the following:

AnalyzeNumericData <- function(x,GroupVar=NA) {

VarList <- names(x)  
NumVars <- length(VarList)  

for (i in (1:NumVars)) {
     if (is.numeric(x[,VarList[i]])) {
       par(mfrow=c(2,2))
         hist(x[,VarList[i]],main=paste("Histogram of ",VarList[i]),xlab=NA)
         boxplot(x[,VarList[i]],main=paste("Boxplot of ",VarList[i]))
      if (!is.na(GroupVar)) {
        boxplot(x[,VarList[i]]~x[,GroupVar],main=paste("Boxplot of ",VarList[i]," by ", GroupVar))
      }   
        # Add some text to bottom right
        # I've tried plot(1)
        # and then text(1,"MyText"), but this only alows me to put text on one place (in the middle of the plot)
    }
  }
}

AnalyzeNumericData(mtcars,"cyl")

The function will create three charts for each numeric variable. I would like to add some text instead of the 4th chart to the bottom right area. I know of text(), however I have to create something like empty chart first in order to use this.

Any ideas appreciated.

Answer 1

AnalyzeNumericData <- function(x,GroupVar=NA) {
    VarList <- names(x)
    NumVars <- length(VarList)

    for (i in 1) {
        if (is.numeric(x[,VarList[i]])) {
            par(mfrow=c(2,2))
            hist(x[,VarList[i]],main=paste("Histogram of ",VarList[i]),xlab=NA)
            boxplot(x[,VarList[i]],main=paste("Boxplot of ",VarList[i]))
            if (!is.na(GroupVar)) {
                boxplot(x[,VarList[i]]~x[,GroupVar],main=paste("Boxplot of ",VarList[i]," by ", GroupVar))
            }
            plot(NA,NA,axes=F,xlim=c(0,10),ylim=c(0,10),xlab="",ylab="")
            text(5,5,labels="MyText")
        }
    }
}

AnalyzeNumericData(mtcars,"cyl")

You can change x and y of text(x,y,labels="MyText") to adjust position of the text according to xlim and ylim.