[R] Double-buffering problem, this time with an example.

[Daniel Carr]

Most of my animations that used to work
on windows() version 2.11.1 and earlier now flash
as if the double buffering is turned off or buffer swapping
is triggered by other events than in the past.

The simplified example below using symbols
should illustrate the problem in a windows environment.

windows()

radius <- 8
n <- 6
ang <- seq(0,2*pi,length=n+1)[-(n+1)]
ca <- cos(ang)
sa <- sin(ang)
size <- c(.1, .3, .5, .7, .9, 1)

colors <-  rainbow(length(size))

for (i in 1:1000){
   radius <- radius*.998
   bnd <- (radius+1)* c(-1, 1)
   cenX <- radius*ca
   cenY <- radius*sa
   symbols(cenX, cenY, circles = size,
           xlim=bnd, ylim=bnd, bg=colors)
}

I have not isolated the version  when the flashing
started but it somewhere between
2.11.1 and 2.14.1.

I did some searching on double-buffering
problems in R but didn't find indications
of this particular problem.

Slowing the animation down did not help.

Dan