[R] raster time series statistics

[Jim Lemon]

I can't test that at the moment as I don't have the libraries. Perhaps later.

Jim

On Tue, Mar 6, 2018 at 11:36 AM,  <Alexander.Herr at csiro.au> wrote:
> Last line in the following (updated) code produces the error
> require(raster)
> require(rts)
> require(stringr)
> r <- raster(ncol=100, nrow=100)
> values(r) <- runif(ncell(r))
> stack(r)->s
> r->rs
> for(i in 1:23){
>  rs[]<-r[]*i
>   addLayer(s,rs)->s
>  print(nlayers(s))
> }
> dt<-list(ID=seq(1:24),month=rep(formatC(1:12,flag=0,width=2),2),
>  year=sort(rep(2016:2017,12)))
>  timelst<-paste0(unlist(dt['year']),'-',unlist(dt['month']),"-01")
> strptime(timelst,format="%Y-%m-%d")->t1
>
> rts(s,time=as.yearmon(t1))->rsts
> subset(rsts,'2017')->r2017
> class(r2017 at time)
> class(rsts at time)
>
> apply.monthly(rsts,mean)
>
>
>
> -----Original Message-----
> From: David Winsemius [mailto:dwinsemius at comcast.net]
> Sent: Tuesday, 6 March 2018 11:10 AM
> To: Herr, Alexander (L&W, Black Mountain) <Alexander.Herr at csiro.au>
> Cc: r-help at r-project.org
> Subject: Re: [R] raster time series statistics
>
>
>> On Mar 5, 2018, at 3:28 PM, <Alexander.Herr at csiro.au> <Alexander.Herr at csiro.au> wrote:
>>
>> Hi List,
>>
>> The following code returns an "Error in as.POSIXlt.character(x, tz, ...) :   character string is not in a standard unambiguous format"
>
> I'm unable to produce that error. Which function was being evaluated to produce the error? I don't see where as.POSIXlt would have been called. You don't have any Date or POSIXt-classed variables. (I did need to also load the stringr package to get str_pad into my workspace.)
>
>>
>> require(raster)
>> require(rts)
>> require(stringi)
>> r <- raster(ncol=100, nrow=100)
>> values(r) <- runif(ncell(r))
>> list(ID=seq(1:24),month=rep(str_pad(1:12, pad = 0,width = 2 ,
>> "left"),2),year=sort(rep(2016:2017,12)))->dt
>> stack(r)->s
>> r->rs
>> for(i in 1:23){
>> rs[]<-r[]*i
>>  addLayer(s,rs)->s
>> print(nlayers(s))
>> }
>> timelst<-paste0(unlist(dt['year']),'-',unlist(dt['month']))
>> rts(s,time=as.yearmon(timelst))->rsts
>> str(rsts at time)
>> apply.monthly(rsts,mean)
>>
>> I was expecting that the statistics accept the yearmonth format of the timeslot, as it allows subsetting.
>> Any suggestions?
>> Thanks
>> Herry
>>
>>       [[alternative HTML version deleted]]
>>
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>
> 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.