[R] Testing for warning inside functions

From: Peter Wolf <s-plus_at_wiwi.uni-bielefeld.de>
Date: Wed 18 May 2005 - 18:51:53 EST


I am looking for a way to get a warning message immediately after an evaluation within a function. To get error messages you can use geterrmessage(). But I found no function that allows me to check for warnings.

Five years ago this questions has been posted but I haven't found any answer.

Thanks for any help.

Peter Wolf


For illustration purpose a simple example follows: you can get warnings after an error occured or after exiting from the function but not at once after "x<-matrix(1:3,2,2)":

> options(warn=0)
> f<-function(x){
   x<-matrix(1:3,2,2)
   print(0)
   warnings() # no warning is shown
   print(1)
   try({xxx})

   print(2)
   print(geterrmessage())
   print(3)

   warnings()
   print(4)
 }
> f()

[1] 0
[1] 1
Fehler in try({ : Objekt "xxx" nicht gefunden Zusätzlich: Warnmeldung:
Datenlänge [3] ist kein Teiler oder Vielfaches der Anzahl der Zeilen [2] in matrix
[1] 2
[1] "Fehler in try({ : Objekt \"xxx\" nicht gefunden\n"
[1] 3

Warning message:
Datenlänge [3] ist kein Teiler oder Vielfaches der Anzahl der Zeilen [2] in matrix
[1] 4
> version

platform i686-pc-linux-gnu
arch     i686
os       linux-gnu

system i686, linux-gnu
status
major 2
minor 1.0
year 2005
month 04
day 18
language R

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