R help - Jun 2012 - readHTMLTable function - unable to find an inherited method ~ for signature "NULL"

Hi R experts,

I have been playing with library(XML) recently and found out that
readHTMLTable workls flawlessly for some website, but it does give me an
error like below

 ... Error in function (classes, fdef, mtable)  :
  unable to find an inherited method for function "readHTMLTable", for
signature "NULL"
let's say..for example, this code works fine

a <-"http://www.zam.com/forum.html?forum=21&p=2"
table_a <- readHTMLTable(a, header = TRUE, which = 1, stringsAsFactors FALSE)

but, this website gives me an error  -

b
<-"http://www.mmo-champion.com/forums/266-General-Discussions/page2"
table_b <- readHTMLTable(b, header = TRUE, which = 1, stringsAsFactors FALSE)

Error in function (classes, fdef, mtable)  :
  unable to find an inherited method for function "readHTMLTable", for
signature "NULL"
I think this is due to the structure of the website but i'm not very
familiar with HTML file, so I'm curious what part of HTML file makes this
happen. (Also it will be great (!) if someone can point out how to output
the second example (like the format that first example outputs..) without
an error

Thanks,

	[[alternative HTML version deleted]]

The second page (mmo-champion.com) doesn't contain a <table>
node.

To scrape the data from the page, you will have to explore its
HTML structure.

   D.

On 6/14/12 9:31 AM, Moon Eunyoung wrote:
> Hi R experts,
> 
> I have been playing with library(XML) recently and found out that
> readHTMLTable workls flawlessly for some website, but it does give me an
> error like below
> 
>  ... Error in function (classes, fdef, mtable)  :
>   unable to find an inherited method for function
"readHTMLTable", for
> signature "NULL"
> let's say..for example, this code works fine
> 
> a <-"http://www.zam.com/forum.html?forum=21&p=2"
> table_a <- readHTMLTable(a, header = TRUE, which = 1, stringsAsFactors
> FALSE)
> 
> but, this website gives me an error  -
> 
> b
<-"http://www.mmo-champion.com/forums/266-General-Discussions/page2"
> table_b <- readHTMLTable(b, header = TRUE, which = 1, stringsAsFactors
> FALSE)
> 
> Error in function (classes, fdef, mtable)  :
>   unable to find an inherited method for function
"readHTMLTable", for
> signature "NULL"
> I think this is due to the structure of the website but i'm not very
> familiar with HTML file, so I'm curious what part of HTML file makes
this
> happen. (Also it will be great (!) if someone can point out how to output
> the second example (like the format that first example outputs..) without
> an error
> 
> Thanks,
> 
> 	[[alternative HTML version deleted]]
> 
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