R devel - Jul 2003 - read.table with option dec=',' (PR#3532)

Full_Name: Antoine Lucas
Version: 1.7.0  (2003-04-16)
OS: Linux
Submission from: (NULL) (193.51.197.253)


I have a problem using read.table:

If in a dataframe, we have a string containing a dot, write.table
will not write any file while using option "dec=','".

Example
> m <- "1.5"
> write.table(m,dec=',')
Error in if (n%%nrowv == 0) value <- value[rep(1:nrowv, length = n), ,  : 
        missing value where TRUE/FALSE needed
In addition: Warning messages: 
1: no finite arguments to min; returning Inf 
2: no finite arguments to max; returning -Inf 

Whereas the contrary write the table:
> m <- "1,5"
> write.table(m,dec='.')
"x"
"1" "1,5"


Best regards

Antoine Lucas

--
Antoine  Lucas        
INRA, Unité de biométrie et     |  Tel 05 61 28 53 34
intelligence artificielle       |  Fax 05 61 28 53 35
http://genopole.toulouse.inra.fr/~lucas

The problem appears to occur in the following expression from write.table():

    x[num] <- lapply(x[num], function(z) gsub("\\.",
",",as.character(z)))

which gives an error when 'num' has length zero (for what it's
worth, the
RHS evaluated to list()).

The error reported occurs when dec= is supplied to write.table() and the 
table has no numeric columns.

Data frame column assignment does not appear able to handle the case where 
the index has zero length, as in the following example

 > x <- data.frame(x="1.5")
 > num <- numeric(0)
 > x[num] <- list()
Error in if (n%%nrowv == 0) value <- value[rep(1:nrowv, length = n), ,  :
         missing value where TRUE/FALSE needed
In addition: Warning messages:
1: no finite arguments to min; returning Inf
2: no finite arguments to max; returning -Inf
 > traceback()
2: "[<-.data.frame"(*tmp*, num, value = list())
1: "[<-"(*tmp*, num, value = list())
 >

Possible fixes are to either guard the expression in write.table() with 'if 
(length(num))' or to change "[<-.data.frame"() to handle this
case.

(I note that S-plus 6.1 under Windows and R1.6.2 under Windows also 
generate an error with this type of data frame assignment, so it does not 
appear to be a new bug with data frame assignment, and is probably best 
fixed with the simple change to write.table())

-- Tony Plate

At Tuesday 03:29 PM 7/22/2003 +0200, lucas@toulouse.inra.fr
wrote:
>Full_Name: Antoine Lucas
>Version: 1.7.0  (2003-04-16)
>OS: Linux
>Submission from: (NULL) (193.51.197.253)
>
>
>I have a problem using read.table:
>
>If in a dataframe, we have a string containing a dot, write.table
>will not write any file while using option "dec=','".
>
>Example
>
> > m <- "1.5"
> > write.table(m,dec=',')
>Error in if (n%%nrowv == 0) value <- value[rep(1:nrowv, length = n), ,  :
>         missing value where TRUE/FALSE needed
>In addition: Warning messages:
>1: no finite arguments to min; returning Inf
>2: no finite arguments to max; returning -Inf
>
>Whereas the contrary write the table:
> > m <- "1,5"
> > write.table(m,dec='.')
>"x"
>"1" "1,5"
>
>
>Best regards
>
>Antoine Lucas
>
>--
>Antoine  Lucas
>INRA, Unité de biométrie et     |  Tel 05 61 28 53 34
>intelligence artificielle       |  Fax 05 61 28 53 35
>http://genopole.toulouse.inra.fr/~lucas
>
>______________________________________________
>R-devel@stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-devel

lucas@toulouse.inra.fr writes:
> Full_Name: Antoine Lucas
> Version: 1.7.0  (2003-04-16)
> OS: Linux
> Submission from: (NULL) (193.51.197.253)
> 
> 
> I have a problem using read.table:
                         ????
 
> If in a dataframe, we have a string containing a dot, write.table
> will not write any file while using option "dec=','".
> 
> Example
> 
> > m <- "1.5"
> > write.table(m,dec=',')
> Error in if (n%%nrowv == 0) value <- value[rep(1:nrowv, length = n), , 
:
>         missing value where TRUE/FALSE needed
> In addition: Warning messages: 
> 1: no finite arguments to min; returning Inf 
> 2: no finite arguments to max; returning -Inf 
> 
> Whereas the contrary write the table:
> > m <- "1,5"
> > write.table(m,dec='.')
> "x"
> "1" "1,5"
Wrong diagnosis: 
> m <- data.frame(1.5,"1.5")
> write.table(m,dec=',')
"X1.5" "X.1.5."
"1" 1,5 "1.5"
> m <- data.frame("a","b")
> write.table(m,dec=',')
Error in if (n%%nrowv == 0) value <- value[rep(1:nrowv, length = n), ,
:
        missing value where TRUE/FALSE needed
In addition: Warning messages:
1: no finite arguments to min; returning Inf
2: no finite arguments to max; returning -Inf

The problem is unrelated to whether or not there are strings with dots
in. The real reason is that you have no numeric columns. If you don't
have any numeric colums, then you can just leave out the dec argument
since it is not supposed to do anything with character columns. The
code in write.table is conditional on dec != "."; that's why the
thing
is unsymmetric in dot and comma.

We should probably treat these borderline cases more gracefully
though. Possibly even at the data frame indexing level: it boils down
to
> x[numeric(0)] <- list()
Error in if (n%%nrowv == 0) value <- value[rep(1:nrowv, length = n), ,
:
        missing value where TRUE/FALSE needed
In addition: Warning messages:
1: no finite arguments to min; returning Inf
2: no finite arguments to max; returning -Inf

and I suppose we might just treat this as a no-op.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907