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Paul Shannon
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@paul-shannon-578
Last seen 9.6 years ago
I have a specific rtracklayer question, and a general S4/help
question.
The specific question: Michael helpfully suggested the 'viewLimits'
parameter to the rtracklayer track method, saying
This is another track line parameter, called viewLimits. See
class?GraphTrackLine.
track (session, "wiggle", viewLimits = c(0, 100)) <- wiggle
Indeed, class?GraphTrackLine mentions that parameter.
But when I call this method (or what I *think* is this method), I get
this:
unused argument(s) (viewLimits = c(80, 100))
That's my specific question. How do I supply viewLimits information
to the track method?
The general question is: how do I navigate the help system, with S4
objects and methods, so I can figure this stuff out for myself?
With R functions, I can type
args (track)
or simply
track
and see, respectively, the parameters and the contents of the body of
the function.
But with generics, args (track) gets me
function (object, ...)
NULL
and then, looking for the definition, I do this (knowing, of course
that it won't work):
> track
standardGeneric for "track" defined from package "rtracklayer"
function (object, ...)
standardGeneric("track")
<environment: 0x10b69b340="">
Methods may be defined for arguments: object
Use showMethods("track") for currently available ones.
> showMethods ('track')
Function: track (package rtracklayer)
object="UCSCSession"
object="UCSCTableQuery"
Is there something like this I should call?
args (track (object='UCSCSession'))
Better yet -- is there a 'R help for S4 classes, objects and methods'
tutorial somewhere?
Thanks!
- Paul
