R help - Apr 2012 - Shewhart Control Charts for Time Series data (qcc package)

Hello everybody!

I am trying to apply qcc function to time series data.

There is an example from documentation:

###
library(qcc)
data(pistonrings)
attach(pistonrings)
diameter <- qcc.groups(diameter, sample)
qcc(diameter[1:25,], type="xbar")
detach(pistonrings)
###

So, we have 5 iteams at each row -> sample size =5

But what should I do if I have just a one dimensional time series data?

###
out.m <- aggregate(pistonrings$diameter, list(sample = pistonrings$sample),
FUN="mean")
qcc(out.m$x, type="xbar") - Error: group sizes must be larger than one
###

Probably in this case samples are a consecutive subsets of the data but
they are not grouped as in an example.

I would like to apply qcc() like rollapply(....width = sample_size, by step) in
such a way that 'width' would stands for a samples taken from an
input data.

Thank you in advance !

--
Kind regards, Alexandr

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