Well,
it looks like it's a perfectly correct approach to bind functions writing
their wrappers by hand.
But I don't want to write them by hand every time I need them.
Being lambda expression, function() is most general, but there must be some
kind of shorter way for such a common task as partial application.
David Winsemius wrote:
>
> How is function() not the correct approach?
>
> > plot_lines <- function(x, ...) plot(x, type="l", ...)
> >
> > plot_lines(1:10, xlim = c(1,5))
>
> > plot_lines(1:10, 11:20, xlim = c(1,5))
>
> Still seems to get the unnamed optional y argument to the plotting
> machinery.
>
> --
> David Winsemius
>
> On Jan 15, 2009, at 4:25 PM, nosek wrote:
>
>>
>> Hello,
>>
>> in a desperate desire of using partial function application in R I
>> fried out
>> the following piece of code:
>>
>> bind <- function( f, ... ) {
>> args <- list(...)
>> function(...) f( ..., unlist(args) )
>> }
>>
>> Its purpose, if not clear, is to return a function with part of its
>> arguments bound to specific values, so that I can for example create
>> and use
>> functions like this:
>> q1 <- bind( quantile, 0.25 )
>> lapply( some_list, q1 )
>>
>> It's been a lot of work and unfortunately is not perfect. My bind
>> applies
>> arguments only using positional rule. What I dream of is a function
>> bind2
>> that would apply keyword arguments, like:
>> plot_lines <- bind2( plot, type="l" )
>> which would return
>> function(...) plot( type="l", ... )
>>
>> How to do this in R?
>>
>> Regards,
>> nosek
>> --
>> View this message in context:
>> http://www.nabble.com/Partial-function-application-in-R-tp21487269p21487269.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
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>
> ______________________________________________
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> PLEASE do read the posting guide
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>
>
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