sdRplot<-function(nx,sl,ny,x){
  #
  # R function that can be used for creating Semantic Differential 
  # (SD) inventory plots.  The input arguments for the function are:
  #   nx - number of levels in scale, e.g., 5
  #   sl - scale labels as a list, e.g. c("SA","A","N","A","SA")
  #   ny - number of descriptor items in the inventory
  #   x - data matrix: 
  #              col1: low-end descriptors 
  #              col2: high-end descriptors
  #              col3-onwards: mean scale values for each group
  # The names of the columns (col 3 and above) of the data matrix 
  # (e.g., dimnames(x[[2]][3:ncol(x)])) are used for labelling 
  # the groups in the legend.
  # Author: Justine Leon A. Uro (justineuro@gmail.com)
  # Date: 19 October 2011 orig.
  #       06 January 2021 rev. to allow plotting for data on only one group (l. 60)
  #       29 July 2021 rev. moved drawing of axis() before legend(); 
  #                         added white opaque background (bg="white"); 
  #                         cex.lab=1.0 for xlab and ylab size
  #
  # Example:
  # low<-c("Serious","Slow","Useless","Tiring","Old","Hard","Long")
  # high<-c("Fun","Fast","Useful","Light","New","Easy","Short")
  # scale<-c("SA","A","N","A","SA")
  # grp1means<-c(4.2,4.6,4.3,4.1,4.5,4.5,4.0)
  # grp2means<-c(3.8,3.9,3.7,4.5,4.4,4.3,4.4)
  # grp3means<-c(4.5,4.7,4.4,4.2,4.6,4.4,3.9)
  # data<-matrix(
  #      cbind(low,high,grp1means,grp2means,grp3means),
  #      nrow=7,ncol=5,byrow=FALSE,
  #      dimnames=list(c("I1","I2","I3","I4","I5","I6","I7"),
  #                    c("Low","High","Grp1","Grp2","Grp3"))
  #     )
  # sdRplot(5,scale,7,data)
  #
  NSCALE<-nx
  NLAB<-ny
  NRW<-nrow(x)
  NCL<-ncol(x)
  NGRP<-ncol(x)-2
  GRPNMS<-dimnames(x)[[2]][3:NCL]
  yval<-NLAB:1
  labvaln<-x[,1]
  labvalp<-x[,2]
  # plot means of first group (only points)
  plot(x[,3],yval,axes=F,pch=1,col=1,type="b",
       xlab="Mean SD Scale Value",ylab="Descriptor",
       cex.lab=1.0, # size of xlab, ylab
       xlim=c(0.30,NSCALE+0.95),
       lab=c(NSCALE,NLAB+2,1),mgp=c(3,1,0),xaxs="r",
       mar=c(7,7,1,1)
  )
  # add title
  title(main="SD Response Profiles",
        sub="",
        cex.sub=0.50
  )
  # draw vertical axes
  axis(1,tck=1,at=c(1:NSCALE),labels=sl,cex.axis=0.60)
  # draw legend with opaque white background
  legend(1.25,NLAB-0.5,title="Legend:",GRPNMS,
         title.col="black",
         text.col=1:NGRP,
         pch=1:NGRP,lty=1:NGRP,
         col=1:NGRP,cex=0.60,
         bg="white"
  )
  # skip this if there is only 1 group
  if(NGRP>1){
    for(i in 2:NGRP){
      points(x[,i+2],yval,pch=i,col=i)
      lines(x[,i+2],yval,pch=i,col=i,lty=i)
    }
  }
  # draw the labels for the tick marks on the axes
  for (i in 1:NLAB)
  {
    text(0.90,yval[i],label=labvaln[i],adj=1,cex=0.70) # cex = size of marks
    text(NSCALE+0.10,yval[i],label=labvalp[i],adj=0,cex=0.70)
  }
}
#
##
###
# Example 1
###
low<-c("Serious","Slow","Useless","Tiring","Old","Hard","Long")
high<-c("Fun","Fast","Useful","Light","New","Easy","Short")
scale<-c("SA","A","N","A","SA")
grp1means<-c(4.2,4.6,4.3,4.1,4.5,4.5,4.0)
grp2means<-c(3.8,3.9,3.7,4.5,4.4,4.3,4.4)
grp3means<-c(4.5,4.7,4.4,4.2,4.6,4.4,3.9)
data<-matrix(
    cbind(low,high,grp1means,grp2means,grp3means),
    nrow=7,ncol=5,byrow=FALSE,
    dimnames=list(c("I1","I2","I3","I4","I5","I6","I7"),
                    c("Low","High","Grp1","Grp2","Grp3"))
   )
sdRplot(5,scale,7,data)
###
# Example 2 (for grp1means only)
###
data1grp<-matrix(
  cbind(low,high,grp1means),
  nrow=7,ncol=3,byrow=FALSE,
  dimnames=list(c("I1","I2","I3","I4","I5","I6","I7"),
                c("Low","High","Grp1"))
)
sdRplot(5,scale,7,data1grp)
#