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Starting with R

3 messages · Anne G, Peter Dalgaard, Paul Bivand

Original
Anne G
# 
I am studying R and within the first 3 lines of
demo("graphics") I get completely stuck.

could you 1. give me the answer so I can move on 2. tell me
how I might find the answer.

On my mac OSX, the first command is equivalent to
get("quartz")()

now get("quartz") would be a regular function format
but what is get () ()? what kind of beast? does get() return
a function?

I run demo("graphics") and of course I want to stop it right
away, without running through the whole demo, how do I STOP
IT! CANCEL IT? (it gets stuck on hit return to continue
lines)

Then I want to look at the program that generated
demo("graphics") and I find a graphic file, but no demo fx.
where is the demo("graphics") fx physically on my computer?
how do I find it on a Mac?

Then I want to list the program, but I can't fine a fx which
list the code of a function.

Sorry, it must seem very basic. But I searched through the
R intro and through the R lists and I can't find the answer.

Thanks for your help

Anne
Peter Dalgaard
# 
Anne G <anne at wjh.harvard.edu> writes:
Well, y'know, sometimes obstacles are more easily handled by walking
around them than by climbing over them. Who said you need to
understand demo("graphics") in order to get to know R? It's a demo, a
show-off of what glitzy graphics we can do, not a tutorial. Actually,
it might be sensible to walk through some of its examples, but the
first couple of setup lines can certainly be skipped.
In this case, yes, exactly. In general, get() returns the R object of
the given name, which may or may not be a funtion.
This is OS and GUI dependent. On unix text terminals you can generally
hit Ctrl-C, in the Windows GUI there's a Stop button (I think), and
Aqua seems to have an Abort button.
Somewhere in the R installation directory. 

system.file("demo/graphics.R",package="graphics")

should tell you exactly, on all systems.
Paul Bivand
# 
in R, the source code for functions can be displayed by typing the function 
name without the brackets. 

Therefore ,

demo

produces the source code

and demo() runs the function - which in this case provides a list of available 
demos.

The source for the graphics demo is a R source file named graphics.R which is 
located in (on my Mandrake linux system, OSX may 
differ) /usr/lib/R/library/graphics/

The source code for functions demonstrated can be similarly displayed, 
although some functions will call C or Fortran modules.

Paul Bivand
On Tuesday 02 Nov 2004 22:35, Anne G wrote: