Timeline for Define the joint pmf of a particle moving randomly on a grid

10 events

when toggle format	what		by	license	comment
Dec 15, 2014 at 20:48	vote	accept	Chris
Dec 15, 2014 at 20:48	comment	added	Chris		Aha I see you are moving outward and to the right! From the pie slice shape I thought you had moved outward and to the left 3 spaces already. Thanks for your solution! Learned a lot :)
Dec 15, 2014 at 19:33	comment	added	Glen_b		It's the same drawing as step 1, but since everything outside the indicated 45-degree "slice of pie" (i.e. $[0,\pi/4]$) can be computed from that slice, we only need to draw/compute what's in that slice (and on its boundary). So from that point on we just draw that part.
Dec 15, 2014 at 15:13	comment	added	Chris		I see, and for $\frac{1}{4}$ of the grid it must be $\frac{1}{4}$. I'm still a little confused about revised step 1.
Dec 15, 2014 at 5:12	comment	added	Glen_b		By the indicated rotational symmetry there are 4 'a' cells, 4 'b' cells and 8 'c' cells in total, which between them must contain all probability.
Dec 15, 2014 at 3:30	comment	added	Chris		I understand most of this, but have a few questions. Why does $p3(a)+p3(b)+2p3(c)=\frac{1}{4}$? In revised step 1, how has q already reached the third dot? At this point I assume we can only move one dot over? Thanks!
Dec 13, 2014 at 3:27	history	edited	Glen_b	CC BY-SA 3.0	added 634 characters in body
Dec 13, 2014 at 3:20	history	edited	Glen_b	CC BY-SA 3.0	added 634 characters in body
Dec 13, 2014 at 3:07	history	edited	Glen_b	CC BY-SA 3.0	added 634 characters in body
Dec 13, 2014 at 0:11	history	answered	Glen_b	CC BY-SA 3.0