NADA Data Frame Format: Wide or Long?
On Thu, 5 Jul 2012, MacQueen, Don wrote:
This example follows exactly the example in ?cenros.
with( subset(yourdataframe, param=='Ag'), cenros(quant,ceneq1) )
This should do a simple censored summary statistica calculation for silver (assuming quant contains your reporting level for censored results, which appears to be the case).
Don, That makes sense to me. I was hoping to avoid subsetting the data frame for each of the 37 chemical parameters, but ... I will review the use of with().
I'd also suggest you try to load your data so that site and param are not factors, though this could depend on your ultimate analysis.
I do need to differentiate results by site and chemical paramater. Many thanks, Rich