On Jan 1, 2010, at 11:20 AM, donahc...@me.com wrote:
Okay, I don't know if I'm blocking because of my other programming
language experience of if I'm just being dense.
I have a data.frame with high,open,low,last,day, and start_time time
columns. What I want to do is get all the rows with the same day
and process each of those columns.
The usual method of doing that sort of operation the application of a
function within categories using tapply. See the examples in:
?tapply
If I was able to run a query against the data.frame I would be want
something like:
result = all the rows where the day is equal to 2007-12-05
Then I would want get max(result["high"]), min(result["low"])
How do I do this? I tired sqldf, but its complaining about
libtcl0.5.8 not being found. I'm on OS X 10.5.8 and haven't yet
tired to install a new version of tcl in /usr/local.
Here's the dataframe:
Nope... nothing came through. Read the posting guide for the proper
way to either include r objects in an email or to attache txt files.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
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