R integration: time series forecast append

[#1]

Hi everyone,

I am trying to append a forecasted time series to a line chart of closing values for a stock. Qlik Sense gives me  'erroe: client specified an invalid argument'. I don't understand what I'm getting wrong. Many thanks for your help.

R.ScriptEval('library(forecast);data<-ts(na.omit(q$Variable1),frequency=1);fit<-auto.arima(data); res<-forecast(fit, level=0.95, h=q$vForecastPeriods); n <- length(q$Variable1); fore <- append(q$Variable1[(q$vForecastPeriods - 1):n],res$mean,after= n - q$vForecastPeriods); $fore;', Sum(Close) as Variable1, vForecastPeriods) 

[Anonymous]

Hi Stan,

Currently, the R extension expects the same number of rows as a result. So you will need to add empty rows for the forecast values into the data that you send to R.

Regards,

Bas.

[#3]

Hi Bas,

Thanks for the advice. I thought that's exactly what I'm doing above: sending in TS to R with its original length and retrieving TS - ForecastPeriods + Forecasts. Further thoughts are appreciated.

[Anonymous · Accepted solution]

Hi Stan,

First, you're using a variable in your expression, you may want to try:

R.ScriptEval('library(forecast);'&

    'data<-ts(na.omit(q$Variable1),frequency=1);'&

    'fit<-auto.arima(data);'&

    'res<-forecast(fit, level=0.95, h=q$vForecastPeriods); '&

    'n <- length(q$Variable1); '&

    'fore <- append(q$Variable1[(q$vForecastPeriods - 1):n],res$mean,after= n - q$vForecastPeriods); '&

    '$fore;',

    Sum(Close) as Variable1,

    $(vForecastPeriods) as  vForecastPeriods )

Second, to help you in troubleshooting check the logs for SSE2Rserve, this should give you an indication of what is wrong in the script.

Regards,

Bas

[#5]

Hi Bas,

Many thanks. It was solved by

$(vForecastPeriods) as  vForecastPeriods

However, I received error with $fore. I just took that $ out of your code and it worked like a charm.

Thanks again!

PS. Any ideas on how to integrate a fan chart are welcome. 

[yuankai0102]

Hi Stan,

Can i have your sample for this? im facing difficulties of mapping back the appended value back with dimension.

Thanks.

[namrata_nm]

Hi Bas,

I am a beginner in Qlik and R.

As you mentioned, that we need need to add empty rows for the forecast values that is sent to R, can you please let me know how can that be done ? And wont it hamper the other visualizations in Qlik ?

Thanks in Advance.

Regards,

Namrata

[otwtm]

I have a similar issue. The forecast period is plotted at the end of the data, but somewhere in the middle.