Re: [R] How to suppress errors from htmlTreeParse() function in XML package?

From: Tony Breyal <tony.breyal_at_googlemail.com>
Date: Wed, 05 Nov 2008 02:26:06 -0800 (PST)

Thank you both Martin and Duncan, each suggestion work beautifully!

re: capture.output() - I don't remember ever coming across this little function before, which is a shame because I can think of several places where it would have been rather useful. R has so many lovely little functions, just wish i could remember them all (though i have found the cheat sheet to be a great time saving resource: http://cran.r-project.org/doc/contrib/Short-refcard.pdf)

re: error = function(...){} - I'm not sure how i missed the 'error=xmlErrorCumulator()' parameter in the '?htmlTreeParse' file , but i am grateful to you for supplying this form of the the parameter because I had no idea you could use an empty function in this way; brilliant!

Cheers,
Tony Breyal

On 4 Nov, 12:37, Tony Breyal <tony.bre..._at_googlemail.com> wrote:
> Dear R-help,
>
> The following code downloads an html document into variable 'doc' and
> then stores an internal representation into variable 'html.tree'. Even
> if the html code is malformed, this still works which is fantastic.
> However, as in the example below, i do get some ouput from R in the
> console which i would like to suppress somehow, so i can keep my
> window a bit cleaner.
>
> I understand that the output is just letting me know that the html
> code is malformed, but for my purposes i can ignore that output. Is
> there a way to achieve this?
>
> ### Example:
> library(RCurl); library(XML)
> doc <- getURL('http://www.google.co.uk/search?q=%22R%20Project
> %22&as_qdr=d1&num=100')
> html.tree <- htmlTreeParse(doc, useInternalNodes = TRUE)
>
> ### Output - this is what i would like to suppress
> Tag nobr invalid
> htmlParseEntityRef: expecting ';'
> htmlParseEntityRef: expecting ';'
> ### etc.
>
> I attempted to use try(expr, silent=TRUE) but that didn't work for me:
>
> >  try(htmlTreeParse(doc, useInternalNodes = TRUE), silent=TRUE)
>
> Many thanks in advance for any help,
> Tony Breyal
>
> ### O/S = Windows Vista Ultimate ###> sessionInfo()
>
> R version 2.8.0 (2008-10-20)
> i386-pc-mingw32
>
> locale:
> LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United Kingdom.
> 1252;LC_MONETARY=English_United Kingdom.
> 1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods
> base
>
> other attached packages:
> [1] XML_1.98-1   RCurl_0.91-0
>
>
>
> ______________________________________________
> R-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.



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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Wed 05 Nov 2008 - 10:48:06 GMT

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