[R] ?for

Prof Brian Ripley ripley at stats.ox.ac.uk
Mon Nov 17 21:27:21 CET 2003


Well ^C or ESC (on Windows GUI) is the answer I would give.

On Tue, 18 Nov 2003, Ray Brownrigg wrote:

> Peter Dalgaard <p.dalgaard at biostat.ku.dk> writes:
> > 
> > Prof Brian Ripley <ripley at stats.ox.ac.uk> writes:
> > 
> > > You have typed a syntactically incomplete statement: this is explained in 
> > > ?help.
> > > 
> > > Hint: ?"for" and help("for") work.
> > 
> > [Original question added back in:
> > On Sun, 16 Nov 2003, Angel wrote:
> > 
> > > I have always been intrigued by why ?for (or ?if,?while,etc) leave R
> > > wanting for more:
> > > > ?for
> > > +
> > > I know the help for these is in ?Control, but I sometimes make the
> > > mistake of typing ?for instead. What is R expecting me to say to finish
> > > the statement?
> > ]
> > Further hint: ? is an operator, syntactically similar to + and -. You
> > can apply operators to the result of a for loop. Consider for example
> > 
> > x <- 1; - for (i in 1:10) x <- x * i
> > 
> > (? has special semantics, but that is not noticed at parse time).
> > 
> Unfortunately the original question still hasn't been answered
> explicitly, not even in ?help.
> Try:
> > ?for
> + (i in 0) 0
> or:
> > ?if
> + (T) T
> or:
> > ?+
> + 0
> 
> So you have to provide the rest of a syntactically complete statement.
> 
> Just to see if you now understand exactly how ? works, what do you
> think:
> ? paste("help")
> will do?
> 
> Ray Brownrigg
> 
> 

-- 
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




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