Joe, What is the definition of tfrom? It's not defined in the gist that you shared. Thanks, Vijay.
On Sun, Mar 30, 2014 at 5:12 PM, Joe Bogner <[email protected]> wrote: > Thanks for the feedback. Confirming your replies below: > > On Sun, Mar 30, 2014 at 4:59 PM, Raul Miller <[email protected]> > wrote: > > > > > Sure you didn't mean for one of those to be distance driven? > > > > > Yes, sorry, the columns are: > > Period, Car, Hours, Miles, Total Cost > > In this example, the car is logging trip start & end time (Hours). It's > logging the # of miles driven. Let's assume the car is getting fueled up > after each trip, so we know the cost. > > > > > Not to mention a 25% reduction in cars... > > > > Yes, I don't think the reduction in cars matters here though > > > > I'd be tempted to set up a variety of simple models for cost, assume a > > linear correlation and then use %. to see what kinds of numbers I get > from > > those. > > > Models might be: > > > > constant cost > > linear cost based on speed > > cost based on square of speed > > cost based distance driven > > cost based on mpg > > > > This is somewhat similar to the path I was starting to go down. I'm not > exactly sure how to make your suggestions actionable yet in terms of a > model. If it's relatively simple to explain, I would be very interested > (and others may be too). > > I was either going to: > 1. Calculate the would-be cost by hold each variable constant. Example: > calculate the cost if the the miles were the same and the speed were the > same and then changing one at a time. > > 2. Calculate the impact by the ratio of each change -- assuming each are > linear and on the same scale. 10% reduction in miles should be a 10% > reduction in cost assuming MPH is held constant... Something like that > > > I'll keep thinking and welcome all other ideas > > I have some crude code started here too that's using inverted tables: > https://gist.github.com/joebo/fd61043076beafeace30 , just to make it more > concrete > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
