R help - Aug 2011 - How to pass different arguments to a function within lapply()?

Hi all,

I have a data frame called "rst", see below:
------------------------------------------------------------------------------------------
# This is a paste able example

# In case you don't have "KernSmooth" package installed, please
uncomment
below line.
# install.packages("KernSmooth")

library(KernSmooth)

rst <- data.frame(hsp = rnorm(23), dal = rnorm(23)

gs <- 350
ts <- seq(1, 353, 16)
                  
bw <- lapply(rst, dpill, x = ts, gridsize = gs)

# If I just want to apply locpoly function seperately
lp.hsp <- locpoly(x = ts, y = rst$hsp, bandwidth = bw$hsp, gridsize = gs)
lp.dal <- locpoly(x = ts, y = rst$dal, bandwidth = bw$dal, gridsize = gs)
--------------------------------------------------------------------------------------------

In above example, I can apply the "locpoly()" to each column of ?rst?.
But
if I want to apply this function to all columns of "rst", I guess I
should
use lapply() function.

However, the "bandwidth", one of the locpoly()'s arguments should
be
different due to different columns of "rst". It means that when R
apply
locpoly() to first column "hsp", the "bandwidth" should be
set as
correspondent bandwidth. 

My problem is, how to pass the "bandwidth" argument to
"locpoly" within
lapply() in terms of different column names? 

My example just tedious if the "rst" has lots of columns. So I wonder
if
there exist more convenient way to get this job done.

Thank you.

-----
Richard Ma
PhD student, Ecology & Remote Sensing
Climate Change Cluster, Department of Environment Science
University of Technology, Sydney
--
View this message in context:
http://r.789695.n4.nabble.com/How-to-pass-different-arguments-to-a-function-within-lapply-tp3728858p3728858.html
Sent from the R help mailing list archive at Nabble.com.

On Aug 8, 2011, at 11:01 PM, Richard Ma wrote:
> Hi all,
>
> I have a data frame called "rst", see below:
>
------------------------------------------------------------------------------------------
> # This is a paste able example
>
> # In case you don't have "KernSmooth" package installed,
please
> uncomment
> below line.
> # install.packages("KernSmooth")
>
> library(KernSmooth)
>
> rst <- data.frame(hsp = rnorm(23), dal = rnorm(23)
>
> gs <- 350
> ts <- seq(1, 353, 16)
>
> bw <- lapply(rst, dpill, x = ts, gridsize = gs)
>
> # If I just want to apply locpoly function seperately
> lp.hsp <- locpoly(x = ts, y = rst$hsp, bandwidth = bw$hsp, gridsize  
> = gs)
> lp.dal <- locpoly(x = ts, y = rst$dal, bandwidth = bw$dal, gridsize  
> = gs)
> --------------------------------------------------------------------------
 > sapply(c("hsp", "dal"), function(x) locpoly(x=ts,
y=rst[[x]],
bandwidth=bw[[x]], gridsize=gs) )
   hsp         dal
x Numeric,350 Numeric,350
y Numeric,350 Numeric,350


-- 
David.
>
> In above example, I can apply the "locpoly()" to each column of  
> ?rst?. But
> if I want to apply this function to all columns of "rst", I guess
I
> should
> use lapply() function.
>
> However, the "bandwidth", one of the locpoly()'s arguments
should be
> different due to different columns of "rst". It means that when R
> apply
> locpoly() to first column "hsp", the "bandwidth" should
be set as
> correspondent bandwidth.
>
> My problem is, how to pass the "bandwidth" argument to
"locpoly"
> within
> lapply() in terms of different column names?
>
> My example just tedious if the "rst" has lots of columns. So I  
> wonder if
> there exist more convenient way to get this job done.
>
> Thank you.
>
> -----
> Richard Ma
> PhD student, Ecology & Remote Sensing
> Climate Change Cluster, Department of Environment Science
> University of Technology, Sydney
> --
> View this message in context:
http://r.789695.n4.nabble.com/How-to-pass-different-arguments-to-a-function-within-lapply-tp3728858p3728858.html
> Sent from the R help mailing list archive at Nabble.com.
>
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David Winsemius, MD
West Hartford, CT