"Patrick E. McKnight" wrote:>
> I have one other problem and then I'll stop and get back to writing. I
> want to plot a missing data matrix (the R matrix a la Little and Rubin)
> to graphically depict where the missing data lie in the matrix. Some
> statistical packages produce a graphical depiction of the missing data
> patterns by plotting the matrix, color-coding the plot with contrasting
> colors for either missing or present.
>
> So far, I have fumbled my way through parts of it but I can't figure
out
> what I am doing wrong. Here is my situation....
>
> Dataset...now sorted the way I want it (thanks)
>
> > newcouple
> id age sex iv1 iv2 dv mdpf
> 2 0 0 0 0 0 0 1
> 3 0 0 0 0 0 0 1
> 5 0 0 0 0 0 0 1
> 7 0 0 0 0 0 0 1
> 9 0 1 0 0 0 0 3
> 6 0 0 1 0 0 0 5
> 10 0 0 0 1 0 0 9
> 1 0 0 0 0 1 0 17
> 4 0 0 0 0 0 1 33
> 8 0 0 0 0 0 1 33
>
> # begin code
>
> # create matrix from data.frame for easy indexing
>
> > dummy <- as.matrix(newcouple)
>
> # create new vectors to later plot
>
> x <- mat.or.vec(1,1)
> y <- mat.or.vec(1,1)
>
> # define default plotting information with par
>
> par(bg="black",pch=22)
>
> # create new frame for plotting
>
> plot.new()
>
> # loop through the matrix to only plot a square for the observations and
> # variables that are missing
>
> for (i in 1:nrow(dummy)){
> for (j in 1:ncol(dummy)){
> if (dummy[i,j] == 1){
>
> # record the coordinates for the missing values to plot with a points
> # call later
>
> y <- append(y,i)
> x <- append(x,j)
> }
> }
> }
>
> # points to plot from my
>
> points(x,y,bg="white")
>
> # end code
>
> The graphical output is just a black window with one point plotted (0,0
> I think). What am I doing wrong?
You did not set the dimensions in plot.window() after calling
plot.new().
I would suggest to use image() instead of your code:
dummy <- as.matrix(newcouple)
image(x = 1:nrow(dummy), y = 1:ncol(dummy), z = dummy,
breaks = c(min(dummy), 0, 1, max(dummy)), col = c(1, 0, 1))
*Your* code can be simplified (loops) and corrected as follows (the
"reversed" colours are the most complicated thing):
dummy <- as.matrix(newcouple)
x <- col(dummy)[dummy==1]
y <- row(dummy)[dummy==1]
par(bg="black", fg="white", col.axis="white",
col.lab="white",
col.sub="white", col.main="white", pch=22)
plot(x, y, type="n")
points(x,y)
> The points function does not appear
> to be adding the extra points the way I want it to add them to the same
> display window.
>
> In the end, I would like to have either a black background with white
> squares (holes) or a white background with black squares to represent
> where the data are missing. I will adjust the squares to an appropriate
> size later. I know that there are other procedures for graphically
> depicting missing data but I (and my colleagues) want this graph for now.
Uwe Ligges
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._