help wrapping findInterval into a function

On Dec 6, 2011, at 5:53 PM, Steve E. wrote:

Bill (and David),

Thank you very much for taking the time to respond to my query.

You were right, I was creating and calling the function exactly as you had
predicted. ?I revised the structure based on your suggestion. ?It runs but
the output is an array of the flags that are not attached to the data
frame,
not a new column in the data frame as was my intention.

So, the new configuration I tried was like this (where DataFrame is not a
real data frame but just the word "DataFrame"):

WQFlags <- function(DataFrame) {DataFrame$CalciumFlag <- with(DataFrame,
ifelse(variable == "CaD_ICP", (dataqualifier <- c("Y", 'Q', "", "A")
[findInterval(DataFrame$value, c(-Inf, 0.027, 0.1, 100, Inf))]),""))
}

I called it using:

WaterQualityData <- WQFlags(WaterQualityData)

Unless you provide either the original data or an unambiguous ( at the level
the R interpreter would see, not at the level of what you see when you print
a dataframe) description of your data you will get at the very best educated
guesses. Use str() or dput().

Again, the output is simply an array of the flags, unattached to a data
frame. ?Can you suggest a way to modify this to make it work as desired,
or,
in the worst case, can I attach the resulting array of flag values?

Do you mean "attach" in the sense of using the R function `attach`? If so,
then please do not. (And please ignore any advice or the examples concerning
that issue you might get from reading Crawley's text.)


--

Good night.

David Winsemius, MD
West Hartford, CT