quartz identify bug (PR#11491)

[...]

There is always the same problem with theses examples :

#1
x=rnorm(10)
qqnorm(x)
identify(x)

#2
x=rnorm(10)
par(mfrow=c(2,1))
plot(x)
qqnorm(x)
identify(x)

identify does not find any points.

Correct, but it is user error.  From the help for identify:

      x,y: coordinates of points in a scatter plot.  Alternatively, any
           object which defines coordinates (a plotting structure, time
           series etc: see 'xy.coords') can be given as 'x', and 'y'
           left missing.

and qqnorm does not do a scatter plot of 'x'.  You need something like 
(look at qqnorm.default)

xx <- qnorm(ppoints(length(x)))[order(order(x))]
identify(xx, x)

(If there were missing values you would need to work harder.)

And please have the courtesy to use your real name and give a signature 
block with your credentials -- it is what is expected in return from the 
expert free consultancy you receive here.

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595