Hi Vijay,
Sorry, it is from here:
http://www.jsoftware.com/jwiki/Essays/Inverted%20Table
tfrom=: <@[ {&.> ]
On Sun, Mar 30, 2014 at 5:45 PM, Vijay Lulla <[email protected]> wrote:
> 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
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