| show {methods} | R Documentation |
Display the object, by printing, plotting or whatever suits its
class. This function exists to be specialized by methods. The
default method calls showDefault.
Formal methods for show will
usually be invoked for automatic printing (see the details).
show(object)
object |
Any R object |
Objects from an S4 class (a class defined by a call to
setClass) will be displayed automatically is if by a
call to show. S4 objects that occur as attributes of S3
objects will also be displayed in this form; conversely, S3 objects
encountered as slots in S4 objects will be printed using the S3
convention, as if by a call to print.
Methods defined for show will only be inherited by simple
inheritance, since otherwise the method would not receive the
complete, original object, with misleading results. See the
simpleInheritanceOnly argument to setGeneric and
the discussion in setIs for the general concept.
show returns an invisible NULL.
showMethods prints all the methods for one or more
functions.
## following the example shown in the setMethod documentation ...
setClass("track", slots = c(x="numeric", y="numeric"))
setClass("trackCurve", contains = "track", slots = c(smooth = "numeric"))
t1 <- new("track", x=1:20, y=(1:20)^2)
tc1 <- new("trackCurve", t1)
setMethod("show", "track",
function(object)print(rbind(x = object@x, y=object@y))
)
## The method will now be used for automatic printing of t1
t1
## Not run: [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12]
x 1 2 3 4 5 6 7 8 9 10 11 12
y 1 4 9 16 25 36 49 64 81 100 121 144
[,13] [,14] [,15] [,16] [,17] [,18] [,19] [,20]
x 13 14 15 16 17 18 19 20
y 169 196 225 256 289 324 361 400
## End(Not run)
## and also for tc1, an object of a class that extends "track"
tc1
## Not run: [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12]
x 1 2 3 4 5 6 7 8 9 10 11 12
y 1 4 9 16 25 36 49 64 81 100 121 144
[,13] [,14] [,15] [,16] [,17] [,18] [,19] [,20]
x 13 14 15 16 17 18 19 20
y 169 196 225 256 289 324 361 400
## End(Not run)