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Distribution of Caches Returned from Pocket Query


IMWhere?
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On many occasions, when building a pocket query (radius about a point or buffer about a route), I'll request 500 caches to be returned. If I get that 500 back, chances are pretty good that more than 500 caches were available.

 

How are those caches distributed??? Two possible examples I can think of:

1) Those points are randomly selected from within the specified area of the radius or the buffer.

2) Those points start at the radius point (or the line of the route) and continue outward until the maximum number has been reached (for example the 500 points were used up within the first 3.5 miles of the 5 mile radius search.

 

Thanks for any help.

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For along a route PQs - the older caches that meet the criteria are selected first (I think)
I remember seeing somewhere that it was the caches closest to the start of the route. I tried finding that source, but I can't find it right now.
I wrote that once, but I was mistaken. Markwell's research indicates that it's the oldest (or lowest GCxxxx codes) that are returned.
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It USED to be pretty clear. I checked it out (gosh) three years ago ?!? :)

 

Somewhere since then the sorting of the results has been manipulated. I'm not sure you can count on the results being truncated if you add attributes to the query, or other conditions - but here's a starting point:

 

If there is an origin, the farthest ones disappear. If it's for a political boundary (like a state), the newest ones drop off. If it's for a route, it's the furthest ones from the route, I believe.

 

I've struck out the route supposition, because I later posted this:

 

Interesting results.

 

I went to a cache rich area - making sure to hit caches within 10 miles of San Francisco, CA. Since there are 565 caches in that radius, I started off site down by Menlo Park and created a route I-280 into San Francisco and over to Oakland and then Richmond. Then I crossed the route back across the Richmond-San Rafael bridge and went back south to Sausalito.

 

I needed to make sure to hit the 10 mile radius, and yet not create a route with 500 miles and a gazillion waypoints. The route was approximately 70 miles with 31 points.

 

I uploaded and ran the query, and the preview said 500. I knew that I was definitely over the limit.

 

After converting it to GSAK and mapping it, here's the results of the 500 caches:

c34c61d3-a689-4022-83ec-2b4569dd90f3.jpg

 

It doesn't appear that there are less caches near the end of the path by Sausalito, but there's a definite concentration near Menlo Park.

 

However, the most interesting thing was looking at the raw data. It appears that the regular caches included were all placed prior to 4/14/2006. That would confirm the limitation that when it looks at the list after getting all of the caches, it returns the 500 oldest caches.

 

BUT WAIT - there's more. There WERE some caches included that were placed more recently and that had newer GC numbers: Earthcaches. There were 5 earthcaches included in the search, and their dates of placement (and inclusion in the GC.com database is backed up by the GC codes) were anywhere from 11/15/2006 to 6/8/2007.

 

Even those however, don't appear to be ALL of the earthcaches. According to the cache list and mapping them, there should be eight Earthcaches included in that route, but only 5 were. Here's the map:

f6a9ddce-c9f1-4494-a284-90b757d6edea.jpg

The red dots are the included earthcaches and the yellow dots are excluded. The three that were eliminated were placed on 11/21/2006, 8/25/2005 and 11/15/2006. Other earthcaches placed on 11/15/2006 and 11/20/2006 WERE included.

 

SO...

 

It looks like the regular caches pick the earliest ones to include, EXCEPT that it tries to include some of the earthcaches as well. How many earthcaches, and why those particular earthcaches were included is still a mystery.

 

So - no explanation, and I can't see any pattern, however, I *AM* quite sure of these two statements

If there is an origin, the farthest ones disappear. If it's for a political boundary (like a state), the newest ones drop off.

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