search for: reef_type_code

Thanks everyone for you help with my last question, and now I have one last one... Here is a sample of my data in .csv format site,time_local,time_utc,reef_type_code,sensor_type,sensor_depth_m,temperature_c 06,2006-04-09 10:20:00,2006-04-09 20:20:00,BAK,sb39, 2, 29.63 06,2006-04-09 10:40:00,2006-04-09 20:40:00,BAK,sb39, 2, 29.56 06,2006-04-09 11:00:00,2006-04-09 21:00:00,BAK,sb39, 2, 29.51 06,2006-04-09 11:20:00,2006-04-09 21:20:00,BAK,sb39, 2, 29.53 06,2006-04...

...up my date and time data manually before I run R. 2- I've read the help on "as.is", and I'm not sure why I need that function in the first line of code. This is what my original data looks like (with header) if this helps answer this this question line.site,time_local,time_utc,reef_type_code,sensor_type,sensor_depth_m,temp 06,2006-04-09 10:20:00,2006-04-09 20:20:00,BAK,sb39, 2, 29.63 06,2006-04-09 10:40:00,2006-04-09 20:40:00,BAK,sb39, 2, 29.56 3. Finally- how does the function "trunc" know to aggregate the data by day? If I wanted to do monthly averages I would need to spec...

Thanks for everyone's input so far, it is greatly appreciated. But I've got one last task I could use some advice on Here are the first few lines of my data set: site,time_local,time_utc,reef_type_code,sensor_type,sensor_depth_m,temperature_c 06,2006-04-09 10:20:00,2006-04-09 20:20:00,BAK,sb39, 2, 29.63 06,2006-04-09 10:40:00,2006-04-09 20:40:00,BAK,sb39, 2, 29.56 06,2006-04-09 11:00:00,2006-04-09 21:00:00,BAK,sb39, 2, 29.51 06,2006-04-09 11:20:00,2006-04-09 21:20:00,BAK,sb39, 10, 29.53 06,2006-0...