David.
> As seen in the following example
>
> library("rjson")
> result <- fromJSON(file = "https://www.semantic-mediawiki.org/w/api.php?action=ask&query=[[Category:City]]|?Capital%20of|?Has%20area&format=json")
> json_data_frame <- as.data.frame(result)
> print(json_data_frame)
>
> which results in:
>
>> library("rjson")
>
> Warning message:
> package ?rjson? was built under R version 3.4.4
>
>> result <- fromJSON(file = "https://www.semantic-mediawiki.org/w/api.php?action=ask&query=[[Category:City]]|?Capital%20of|?Has%20area&format=json")
>> json_data_frame <- as.data.frame(result)
>
> Error in (function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE, :
> arguments imply differing number of rows: 0, 1
>
>> print(json_data_frame)
>
> Error in print(json_data_frame) : object 'json_data_frame' not found
>
>>
>
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Evans, Richard K. (GRC-H000)
> Sent: Tuesday, May 08, 2018 11:52 AM
> To: David Winsemius
> Cc: r-help at r-project.org
> Subject: Re: [R] help with json data from the web into data frame in R
>
> Right. I'm trying to access a server within my organization which has a cert error that I cannot fix.
>
> The example link I provided was to a site on the web that does not have the cert error.
>
> From the linux shell I use the "-k" switch with cURL to ignore cert errors.. is there an equivalent in the R world?
>
> -Rich
>
>
> -----Original Message-----
> From: David Winsemius [mailto:dwinsemius at comcast.net]
> Sent: Tuesday, May 08, 2018 11:48 AM
> To: Evans, Richard K. (GRC-H000)
> Cc: Eric Berger; r-help at r-project.org
> Subject: Re: [R] help with json data from the web into data frame in R
>
>
>> On May 8, 2018, at 8:36 AM, Evans, Richard K. (GRC-H000) <richard.k.evans at nasa.gov> wrote:
>>
>> I?ve been tinkering and discovered that the link I need to read json data from is ?https? and there is a certificate warning that I have to click through from a browser. That might be my issue. Is there any way in the json package to tell it to ignore self-signed cert errors in a url?
>
> I didn't have that issue when using the link you offered:
>
> library(jsonlite)
> myJSON <- fromJSON( url("https://www.semantic-mediawiki.org/w/api.php?action=ask&query=%5B%5BCategory:City%5D%5D&format=json") )
>
> # results in a complex list (not trivially reducible to a dataframe:
>
> str(myJSON)
> List of 1
> $ query:List of 5
> ..$ printrequests:'data.frame': 1 obs. of 5 variables:
> .. ..$ label : chr ""
> .. ..$ key : chr ""
> .. ..$ redi : chr ""
> .. ..$ typeid: chr "_wpg"
> .. ..$ mode : int 2
> ..$ results :List of 39
> .. ..$ File:2166320938 5cfc9ec72a z.jpg :List of 6
> .. .. ..$ printouts : list()
> .. .. ..$ fulltext : chr "File:2166320938 5cfc9ec72a z.jpg"
> .. .. ..$ fullurl : chr "https://www.semantic-mediawiki.org/wiki/File:2166320938_5cfc9ec72a_z.jpg"
> #-----trimmed-----------
>
> David
>
>>
>> -Rich
>>
>> From: Eric Berger [mailto:ericjberger at gmail.com]
>> Sent: Tuesday, May 08, 2018 11:31 AM
>> To: Evans, Richard K. (GRC-H000)
>> Cc: r-help at r-project.org
>> Subject: Re: [R] help with json data from the web into data frame in R
>>
>> Hi Rich,
>> Take a look at the function fromJSON found in the rjson package.
>> Note that the Usage in the help page: ?fromJSON names the second
>> argument 'file' but if you look at the description the argument can be a URL.
>>
>> HTH,
>> Eric
>>
>>
>> On Tue, May 8, 2018 at 6:16 PM, Evans, Richard K. (GRC-H000) <richard.k.evans at nasa.gov<mailto:richard.k.evans at nasa.gov>> wrote:
>> Hello
>>
>> I am able to construct a url that points to some data online in the JSON format. See an example at [0].
>>
>> I would like to work with this data as a dataframe in R.
>>
>> I know that there is a package for handling json data [1] but it assumes the data is in a local file but It is not clear to me how to request the data from the web in an R script and get the json data converted into a data frame in R.
>>
>> Can anyone provide a basic example or some guidance please?
>>
>> -Rich (revansx)
>>
>> [0]
>> https://www.semantic-mediawiki.org/w/api.php?action=ask&query=[[Catego
>> ry:City]]&format=json<https://www.semantic-mediawiki.org/w/api.php?act
>> ion=ask&query=%5b%5bCategory:City%5d%5d&format=json>
>> [1] https://www.tutorialspoint.com/r/r_json_files.htm
>>
>> ______________________________________________
>> R-help at r-project.org<mailto:R-help at r-project.org> mailing list -- To
>> UNSUBSCRIBE and more, see 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.
>>
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> 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.
>
> David Winsemius
> Alameda, CA, USA
>
> 'Any technology distinguishable from magic is insufficiently advanced.' -Gehm's Corollary to Clarke's Third Law
>
>
>
>
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
David Winsemius
Alameda, CA, USA
'Any technology distinguishable from magic is insufficiently advanced.' -Gehm's Corollary to Clarke's Third Law