R help - May 2006 - trouble with plotrix package

Hello list,

I wrote a simple program to plot data on polar axes, taking advantage of 
the plotrix package and its function radial.plot. The basic plot works 
fine, but I am having difficulties with the formatting. There are three 
problems, but I thought I would attack them one at a time. Here is the 
first:

If my data set contains values with all vector lengths between 0 and 100 
(and various angles), and I set rp.type="s", I get a nice
"bullseye" type
plot with the data shown on a background of concentric circles labeled 
appropriately. On the other hand, if my data only contain vector length 
values from, say, 80 to 90 then the first concentric ring is at 80, and 
five more rings are scrunched between 80 and 100.

It looks like there is an autoscaling feature turned on that says make a 
fixed number of rings starting at a nice value below the user's lowest 
data value and extending to a nice value above.

There is a switch to set the upper bound on rings (radial.lim) but I don't 
see a way to specify the lower bound. What I want is a "bullseye" plot
that goes from my start value (first ring at 10) to my end value (last 
ring at 100) independent of the data range.

Thanks!!

=Randy
R. Zelick				email: zelickr at pdx.edu
Department of Biology			voice: 503-725-3086
Portland State University		fax:   503-725-3888

mailing:
P.O. Box 751
Portland, OR 97207

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Portland, OR 97201

Randy Zelick <zelickr <at> pdx.edu> writes:
> 
> There is a switch to set the upper bound on rings (radial.lim) but I
don't
> see a way to specify the lower bound. What I want is a "bullseye"
plot
> that goes from my start value (first ring at 10) to my end value (last 
> ring at 100) independent of the data range.
> 
> Thanks!!
> 
> =Randy> 
  I would suggest dumping radial.plot to a file and making
the following hacks:

  - change the default value of radial.lim from NA to range(lengths)
  - delete the second and third lines of code that set radial.lim to
max(lengths) if it is NA
  - change grid.pos to be set to pretty(radial.lim)

  this behavior seems more sensible to me -- if one wanted to
make it backward compatible one could hack it with something like

if (!missing(radial.lim) && length(radial.lim)==1) radial.lim <-
c(min(lengths),radial.lim)

 perhaps Jim Lemon will want to incorporate these changes

  the following verbose diff file says the same thing.

***************
*** 2,12 ****
      label.prop = 1.1, main = "", xlab = "", ylab =
"", line.col = par("fg"),
      mar = c(2, 2, 3, 2), show.grid = TRUE, grid.col = "gray",
      grid.bg = par("bg"), point.symbols = NULL, point.col = NULL,
!     show.centroid = FALSE, radial.lim = NA, ...)
  {
      length.dim <- dim(lengths)
-     if (is.na(radial.lim))
-         radial.lim <- max(lengths)
      if (is.null(length.dim)) {
          npoints <- length(lengths)
          nsets <- 1
--- 2,10 ----
      label.prop = 1.1, main = "", xlab = "", ylab =
"", line.col = par("fg"),
      mar = c(2, 2, 3, 2), show.grid = TRUE, grid.col = "gray",
      grid.bg = par("bg"), point.symbols = NULL, point.col = NULL,
!     show.centroid = FALSE, radial.lim = range(lengths), ...)
  {
      length.dim <- dim(lengths)
      if (is.null(length.dim)) {
          npoints <- length(lengths)
          nsets <- 1
***************
*** 23,29 ****
          radial.pos <- matrix(rep(radial.pos, nsets), nrow = nsets,
              byrow = TRUE)
      if (show.grid) {
!         grid.pos <- pretty(c(lengths, radial.lim))
          if (grid.pos[1] <= 0)
              grid.pos <- grid.pos[-1]
          maxlength <- max(grid.pos)
--- 21,27 ----
          radial.pos <- matrix(rep(radial.pos, nsets), nrow = nsets,
              byrow = TRUE)
      if (show.grid) {
!       grid.pos <- pretty(radial.lim)
          if (grid.pos[1] <= 0)
              grid.pos <- grid.pos[-1]
          maxlength <- max(grid.pos)
***************
*** 96,98 ****