[R] how to transform db query result into a set of timeseries ?

[Joshua Ulrich]

There's no reason to create multiple xts objects if you intend to
merge them all into one object.  You say the user can select
timeseries, so I assume you have column names in a vector.  If so, you
can do something like this:

series <- c("M", "G", "N")
...
zonnen <- xts(df[,series], as.POSIXct(df$Date))
dygraph(zonnen)

On Mon, Sep 5, 2016 at 3:28 PM, Stef Mientki <stef.mientki at gmail.com> wrote:
> hello,
>
> I've a number of timeseries into a database and want to display these
> timeseries into graph.
>
> Now the code below works well, but as the user can select which timeseries
> should be shown (up to 20 timeseries) the code below should be dynamic and
> can be quiet large and complex.
>
> Is there an easier way to convert a database result into timeseries accepted
> by dygraph ?
>
>     SQL <- "select Date, M, G, N from Compare_Model"
>     df <- dbGetQuery ( con, statement = SQL )
>
>     zon1 <- xts ( df$M,  as.POSIXct ( df$Date, format="%Y-%m-%d %H:%M:%S") )
>     zon2 <- xts ( df$G,  as.POSIXct ( df$Date, format="%Y-%m-%d %H:%M:%S") )
>     zon3 <- xts ( df$N,  as.POSIXct ( df$Date, format="%Y-%m-%d %H:%M:%S") )
>
>     zonnen <- Reduce ( function(...) merge(..., all=TRUE ), list ( zon,
> zon2, zon3 ))
>
>     dygraph ( zonnen )
>
>
> thanks,
>
> Stef
>
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