Purchase DC formula

[Achan hiArusa]

Alright, after some experimentation I found a formula with a R^2 value of 0.999 for converting US dollars to purchase DCs:

y = 7.9781468073465 * log x - 6.3440017626864

where y is the purchase DC and x is the price in US dollars, round normally. It doesn't fit with DC 2 ($5), DC 3 ($12), and DC 7 ($55).

The inverse formula isn't so neat and tidy, but I'll give it to you anyway.

y = (1 +/- 0.063) * 10 ^ (0.125312836895649 x + 0.796398865272266)

This formula doesn't work for purchase DCs of 8 or less. I tried to do a fourier fit for the uncertainty, but I will have to work on it a little further in the future.

 

[Gilwen]

Alright, after some experimentation I found a formula with a R^2 value of 0.999 for converting US dollars to purchase DCs:

y = 7.9781468073465 * log x - 6.3440017626864

where y is the purchase DC and x is the price in US dollars, round normally. It doesn't fit with DC 2 ($5), DC 3 ($12), and DC 7 ($55).

The inverse formula isn't so neat and tidy, but I'll give it to you anyway.

y = (1 +/- 0.063) * 10 ^ (0.125312836895649 x + 0.796398865272266)

This formula doesn't work for purchase DCs of 8 or less. I tried to do a fourier fit for the uncertainty, but I will have to work on it a little further in the future.

I want your free time man!

-Gil

 

[Achan hiArusa]

Thanks

It was just a matter of plugging in the values from the extended table from Future d20 into a Microsoft Excel sheet, comparing the values to 10 log price, doing a trend line fit and then pulling out a pen and paper for the final values. The Fourier fit isn't going as well as I want and I have to learn a little bit more about Origin 7.0 before I can do it.