Having problems with calculations and minimum and maximums
In my database I have data collected every 30 minutes for each day, for each month during "a growing season". To calculate Growing Degree Days (GDD): If the temperature is 10*c or below, I use 10*c (Tmin), if it's 30*c or above I use 30*c (TMax), else the temp*c. It's easy to get the min and max for the day, but what I'm having problem with is using the min & max for the day to plug into the formula (Tmin + Tmax)/2-10*c. If I find one day it's works. When I find several months of data, it takes the Tmin and Tmax for the found set, when I need it calculated for each day. I would like to produce a report with a sub summary by day, month and period selected for a report or export. I would appreciate any help you can provide or if you can point me in a direction.