[R] warnings from hist(): parameter XXX couldn't be set in high-level plot functionN

[Uwe Ligges]

George_Heine at blm.gov wrote:

> 
> 
> 
> Hello -
> 
> This is not a real problem, just an annoyance.  Sometimes, but not always,
> I get a set of strange warnings from hist().  Example follows.
> 
> ############################
> #Produce a histogram of start dates for a set of field measurements.
> 
> # I didn't reproduce all the dates, because not sure it's relevant, but
> here's a sample.
> # Note the invalid date in the fifth element.
> 
>>StartDate[sample(1:length(StartDate),20)]
> 
>  [1] "2004-08-26" "1997-09-08" "2004-08-19" "1997-09-08" "0999-07-20"
>  [6] "2001-11-28" "2000-11-02" "1997-09-08" "2004-08-19" "2004-10-28"
> [11] "1997-09-08" "1997-09-09" "1997-09-08" "1998-09-08" "1997-09-09"
> [16] "1997-09-08" "2004-10-28" "1997-09-08" "2004-08-19" "1997-09-08"
> 
>>years<-as.Date(c(#
> 
> +    "1995-01-01","1996-01-01","1996-01-01",
> +    "1997-01-01","1998-01-01","1999-01-01","2000-01-01","2001-01-01",
> +    "2002-01-01","2003-01-01","2004-01-01","2005-01-01"))
> 
> 
>>years
> 
>  [1] "1995-01-01" "1996-01-01" "1996-01-01" "1997-01-01" "1998-01-01"
>  [6] "1999-01-01" "2000-01-01" "2001-01-01" "2002-01-01" "2003-01-01"
> [11] "2004-01-01" "2005-01-01"
> 
> 
>> TimeSpan<-as.integer(difftime(StopDate,StartDate))
> 
> Warning message:
> NAs introduced by coercion
> #  Note:  NAs correspond to 3 invalid dates, apparently typos
> 
> 
>>h<-hist(StartDate[TimeSpan>0 & StartDate>years[1]], breaks=years, freq=T,
> 
> +       main="",xlab="",ylab="number of sites", col="grey")
> Warning messages:
> 1: parameter "main" couldn't be set in high-level plot() function
> 2: parameter "ylab" couldn't be set in high-level plot() function
> 3: parameter "main" couldn't be set in high-level plot() function
> 4: parameter "ylab" couldn't be set in high-level plot() function
> #########################################3
> 
> The resulting histogram was generated, and the plot labels main, xlab,
> ylab, were as expected.  Just curious about what the warning messages mean.
> Why are there two warnings each about 'main' and 'ylab', and none about
> 'xlab'?   Another puzzling thing is that this message does not always
> occur,
> Searched the FAQ and the mail archives and couldn't find anything helpful.


Because xlab is a formal argument of the Date method of hist(), while 
ylab and main are not and passed to underlying functions via the "..." 
argument. Functions like axis() not knowing about arguments like main 
and ylab complain by sending a warning. Hence you can ignore these warnings.



>  By the way, is there a way to use seq() to generate something like the
> "years" sequence above?

[Gabor G. has already answered this one.]


Uwe Ligges


> I'm using R 2.0.1 (precompiled version for windows.)
> 
> Thanks for your help !
> <>=<>=<>=<>=<>=<>=<>=<>=<>=<>=<>
> George Heine, PhD
> Mathematical Analyst
> National IRM Center
> U.S. Bureau of Land Management
> voice   (303) 236-0099
> fax       (303) 236-1974
> cell      (303) 905-5382
> pager   gheine at my2way.com
> <>=<>=<>=<>=<>=<>=<>=<>=<>=<>=<>
> 
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