[R] Problem with adapt package

[Martin Maechler]

>>>>> "JonR" == Jonathan Rougier <J.C.Rougier at durham.ac.uk> writes:

    JonR> Hi Anthony,
    JonR> Anthony Tate wrote:
    >> 
    >> I am having problems using the adapt add on package to integrate a function
    >> over 2 dimensions, using the following code.
    >> 
    >> library(adapt)
    >> 
    >> alb1 <- function(p,X,th,alpha){
    >> y <- p[1]; z <- p[2]
    >> c <- sqrt((X + z*tan(th))^2 + z^2)
    >> r <- sqrt(c^2 + y^2)
    >> exp(-alpha*r) / r^3
    >> }
    >> 
    >> x <- 0.05
    >> y <- x
    >> w <- 0.5
    >> delta <- 0.1
    >> czang <- pi/4
    >> alpha <- 15.0
    >> y[i] <- adapt(ndim=2, lower=c(0,0), upper=c(w,delta),
    >> minpts=1000, maxpts=10^6, funct=alb1,  eps=0.005,
    >> X=x, th=czang, alpha=alpha)$value
    >> 
    >> The code gives the following error
    >> 
    >> Error in function (p, X, th, alpha)  : Argument "X" is missing, with no default

    JonR> This is a bug that I thought we had squashed.  Crudely there is a
    JonR> "..."  missing in the line "ff<-functn".  I have a feeling that
    JonR> Martin fixed this with some tricky code using ".Alias", but the
    JonR> fix has not appeared on CRAN.  Martin?!

Yes, this definitely rings a bell!  Indeed I had fixed something like that,
submitted to Thomas, who had put it into the integrate package then.

"adapt" has been packaged by Brian Ripley and I haven't checked whether
adapt() was the same as formerly in the integrate package...

Okay, yes, apply (something like) the following patch

--- R/adapt.R.~1~	Wed Jun 27 17:22:38 2001
+++ R/adapt.R	Fri Jun 29 13:38:41 2001
@@ -7,12 +7,14 @@
     keep.trying<-is.null(maxpts)
     if (is.null(maxpts)) maxpts<-max(minpts,500)
   
-    ## fudge for 1-d functions
-    if (ndim == 1) {
+    if (ndim == 1) { ## fudge for 1-d functions
         warning("Using integrate() in base R for 1-d integration")
         return(integrate(functn,lower,upper,subdivisions=maxpts,rel.tol=eps,...))
     }
-    else ff<-functn
+    else ff <-
+        if(length(list(...)) && length(formals(functn)) > 1)
+            function(x) functn(x, ...)
+        else .Alias(functn)
   
     ## Check to make sure that upper and lower are reasonable lengths
     ## Both the upper and lower limits should be at least of length ndim


-----------

Note that the point is not in using .Alias() {which could be omitted},
but in the extra

 if(length(list(...)) && length(formals(functn)) > 1)
	     function(x) functn(x, ...)
	 else 

--

Martin Maechler <maechler at stat.math.ethz.ch>	http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum  LEO D10	Leonhardstr. 27
ETH (Federal Inst. Technology)	8092 Zurich	SWITZERLAND
phone: x-41-1-632-3408		fax: ...-1228			<><
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._