3 ms·
Surprised no one on HN calculated this already. S = P / Var(P) Numbers of pixels: 13,6,16,29,6,16,13,6,19,13,19,9,26; followed by the large one. Mean ~ 14.692
by jychang 14y ago
Surprised no one on HN calculated this already.
S = P / Var(P)
Numbers of pixels: 13,6,16,29,6,16,13,6,19,13,19,9,26; followed by the large one.
Mean ~ 14.692;
Using Sample Variance ~ 53.397;
Using Population Variance ~ 49.289;
SalesPerPixel(Sample) ~ .275
This doesn't seem right, where does the math screw up?
That said, this isn't very useful. The only time someone will show sales graphs is for special events... aka when it DOESN'T follow a possion distribution.
- jstanley 14y agoBut, just like you did, the special event can be excluded from the poisson calculation. Then you know the scale and can figure out the values for the special event.
- sesqu 14y agoI think you underestimated the pixel counts. It's hard to be precise because of the bleeding, likely due to scaling, but adding one to the pixel counts results in a much more reasonable 0.294 sales per pixel. This would indicate the special event precipitated 25 sales.