[datatable-help] there is no package called ‘xts’

[Matthew Dowle]

Indeed! Great stuff Michael.

I suppose that error ("Error in loadNamespace(name) : there is no 
package called ‘xts’") is yet another valid bug (sigh), if you wouldn't 
mind filing please Sam.

Thanks,
Matthew


On 24.04.2013 02:16, Eduard Antonyan wrote:
> This is great, a lot of cool stuff in one post!
>
> On Apr 23, 2013, at 7:42 PM, Michael Nelson
> <michael.nelson at sydney.edu.au> wrote:
>
>> From the help for data.table::last
>>
>>  If x is a data.table, the last row as a one row data.table. 
>> Otherwise, whatever xts::last returns.
>>
>>
>> calling lapply(.SD, last) will call last on each column in .SD. 
>> Columns within a data.table aren't  data.tables thus `xts::last` is 
>> called.  xts is on the suggests list for data.table,
>>
>> you could use
>>
>> install.packages('data.table, dependencies = 'Suggests')
>>
>> or manually installed xts.
>>
>> OR
>>
>> frame[, last(.SD), by = id]
>>
>> would work without needing xts
>>
>> as would
>>
>> frame[, .SD[.N], by = id]
>>
>> or without having to construct .SD (which is time consuming)
>>
>> frame[frame[, .I[.N],by = id]$V1]
>>
>> or
>>
>> setkey(frame, id)
>>
>> frame[unique(id), mult = 'last']
>>
>> ________________________________________
>> From: datatable-help-bounces at lists.r-forge.r-project.org 
>> [datatable-help-bounces at lists.r-forge.r-project.org] on behalf of Sam 
>> Steingold [sds at gnu.org]
>> Sent: Wednesday, 24 April 2013 7:57 AM
>> To: datatable-help at lists.r-forge.r-project.org
>> Subject: [datatable-help] there is no package called ‘xts’
>>
>> Hi,
>> I got this:
>>
>>> dt <- frame[, lapply(.SD, last) ,by=id]
>> Finding groups (bysameorder=TRUE) ... done in 0.126secs. 
>> bysameorder=TRUE and o__ is length 0
>> Optimized j from 'lapply(.SD, last)' to 'list(last(country), 
>> last(language), last(browser), last(platform), last(uatype), 
>> last(behavior))'
>> Starting dogroups ... Error in loadNamespace(name) : there is no 
>> package called ‘xts’
>> Calls: [ -> [.data.table -> last -> :: -> getExportedValue -> 
>> asNamespace -> getNamespace -> tryCatch -> tryCatchList -> tryCatchOne 
>> -> <Anonymous>
>>
>> the help for last does mention xts, but I don't have it installed.
>> do I need to?
>>
>> --
>> Sam Steingold (http://sds.podval.org/) on Ubuntu 12.10 (quantal) X 
>> 11.0.11300000
>> http://www.childpsy.net/ http://ffii.org http://think-israel.org
>> http://mideasttruth.com http://memri.org http://camera.org
>> Ernqvat guvf ivbyngrf QZPN.
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