Hi everyone,

I have the following:

sqldf("select Premie,count(tpounds) N,avg(tpounds) Avg_Weight,
  stddev_samp(tpounds) StdDev
  from children
  group by Premie
  having !is.na(Premie)")

sqldf() does not like the !is.na(Premie) specification. How does one
exclude a "missing" group in an aggregated query using sqldf()?

Thanks!

Dan

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