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Change the shape of PQ


capsai

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Hi to everyone,

 

i would like to propose changing the shape of the pocket query results, when not choosing a specified country or state.

 

Just imagine you want to cover a special area with two pocket queries, you will have the following problem:

 

cu6m3nu96aqfiu9w9.png

 

I have two suggestions for a better shape:

First one:

cu6m8z4zkjqmwjont.png

 

Second one:

cu6m98q9xawwmt6e1.png

 

With one of both suggestions, it would be great to have a kind of automatic optimizer, which optmizies pqs for one area in that way that there are no caches in both pq.

 

Honestly, i am not sure if this is easy to implement, but it's just a suggestion and maybe it will be realized.

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I'm not really sure why people are so concerned if there is overlap. Back when you could have 5 PQ with only 500 caches per day, sure overlap cut into the total caches you could download. Perhaps when the limit was changed to 5 x 1000 there were still people who wanted to cover an area with ~5000 caches and the overlap meant they would get some number fewer than 5000. But now the limit is 10 x 1000 caches per day. If you don't get your full 10000 caches because of overlap are you really impaired? In any case as stated above, you can use date placed in your PQ to get more than 1000 caches in a circular area and reduce the number lost to overlap.

 

The circular shape has a unique property in that the distance of the cache from the center point is computed and can be used to limit the PQ to the 1000 closest caches. Other shapes would likely have to be implemented as a circle that circumscribes the shape. After eliminating the caches outside the shape, if there are still more than 1000 caches those most distant from the center of the circle would be eliminated. Trying to adjust the sizes of the shapes so they have fewer than 1000 cache (so you don't miss caches) but as close to 1000 as possible (so you don't have to use up extra PQs) would be far more complicated and harder to explain than the overlap in the current system.

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If you have the limit on the points loaded to the device, and not the unique points in the device, than it limits highly the capability of your device.

 

I'm not sure if 2000 limit applies to the unique points or points at all, but after bad experience of finding myself without the caches on the train station, I'd simply no risk putting in my Garmin the PQS with more than 2000 points.

 

So for me, the ability to generate rectangular PQs would make perfectly sense. I haven't yet learned how to make that in GSAK, but GSAK is not core functionality, and it doesn't work on Linux, so it's not a viable option if you don't plan to keep your windows device.

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If you have the limit on the points loaded to the device, and not the unique points in the device, than it limits highly the capability of your device.

 

I'm not sure if 2000 limit applies to the unique points or points at all, but after bad experience of finding myself without the caches on the train station, I'd simply no risk putting in my Garmin the PQS with more than 2000 points.

 

So for me, th e ability to generate rectangular PQs would make perfectly sense. I haven't yet learned how to make that in GSAK, but GSAK is not core functionality, and it doesn't work on Linux, so it's not a viable option if you don't plan to keep your windows device.

 

You never said what device you had. Newer devices hold way more than that up to infinite for the latest Garmin. If the limit is 2000 and you load one twice it only counts once because it only uses one. That being said it is a good idea to not have that happen. With GSAK you can export the limit for your device as one file new each time and overwrite the old file.

 

If you are leaving windows then gsak won't work but while you have it go up to geocaching.com access on the top, click Get Caches, Click Rectangle on the left and then Google map on the right. Place the rectangle where you want it and then Return Coordinates and fill out the two pages of filter info. That info can be saved for later use.

 

GSAK has been successfully run on Linux and here is the forum http://gsak.net/board/index.php?showforum=48

Edited by Walts Hunting
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While I see the logic here, I don't really find it that much of a problem. But if it were to be implemented, I would suggest rather than changing the shape of the existing PQ, instead PQs could be specified as they are now -- the N caches nearest a point -- and then a second approach could be added that would allow the user to specify a shape within which all caches are returned. They're really 2 different things, and I prefer the first one even with its limitations.

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Or just do your PQs by 'date placed'. Already available. Works nicely. Accomplishes the same thing.

This only works when you can look at multiple PQs at the same time. Delorme PN-40s and -60s can't do that, for example.

Either I'm missing something, or this would be a problem no matter what shape the PQ, then?

 

I use the "date placed" split to get ~7500 caches across 8 PQs with no overlap. Works nicely; every few months when the latest PQ gets up close to 1000 caches I go and fiddle the dates a bit, then add a new PQ. Yes, I'd rather have one 10000-cache PQ than eight to ten 1000-cache ones (since I have to import each individually into Geosphere), but now that we can run 10 per day anyway, it's really not that big a deal.

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Or just do your PQs by 'date placed'. Already available. Works nicely. Accomplishes the same thing.

This only works when you can look at multiple PQs at the same time. Delorme PN-40s and -60s can't do that, for example.

Either I'm missing something, or this would be a problem no matter what shape the PQ, then?

I didn't mean to argue for shaped PQs, since I'm not that interested in them. But if the goal is to cover a larger area, the date placed trick is useless for PN's, so we return to the observations that shaped PQs would allow the most coverage with the fewest PQs. Yes, the PN user has to switch PQs in any case, but with shaped PQs he'll be able to create and carry fewer PQs and switch less often.

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Or just do your PQs by 'date placed'. Already available. Works nicely. Accomplishes the same thing.

No, it doesn't -- it still generates, at best, a very large circle, which may be less than an ideal shape for some users (myself included) due to geographic peculiarities where the user caches. A large part of the circle itself may be 'wasted space' at times, unless the circle is pulled back to a point of tangency with the 'unusable' area, in which case, gaps are now formed. This has been argued at length in other threads. But no, it does not 'accomplish the same thing' for many of us.

 

More to the point, the computational power required to bounds check to see if a point lies within a rectangular area (vs radius around a point) is significantly less. I'm surprised they haven't considered it for that reason alone.

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More to the point, the computational power required to bounds check to see if a point lies within a rectangular area (vs radius around a point) is significantly less. I'm surprised they haven't considered it for that reason alone.

Oh man I hate it when the machine is made to do more work. :huh:

 

How often do we see pick the "simpler" method to save the computation effort on a machine that was designed to compute in the first place. Sure there may be some times when the less compute intensive method will compute a result faster and that result is adequate for what people are doing.

 

If you live in the middle latitudes and not near 180° Longitude, it's pretty easy for a person to understand selecting caches in a "rectangle" bounded by latitude and longitude. But strange things happen when you go from + to - across 180°, or trying to use this method to find a rectangle that includes the north or south pole. And even though you might argue that people don't live a the north pole :santa: and 180° is mostly in the middle of the Pacific ocean, the system will still have to take these locations into account because someone will no doubt want a PQ of all the caches in Antarctica.

 

Distance from a point works everywhere and people pretty much understand what it means. It has the additional capability of being able to sort from nearest to farthest. And that can be used to limit a PQ to the 1000 nearest caches. To do this with the "rectangular" shape one would still need to compute distances.

 

Many of us merge all of our PQs into one to send to the unit using GS... oh, never mind. It doesn't work on a Mac, so we should not discuss it.

GPSBabel works on various version of OSx and Linux. You can merge PQ, you can even filter them to remove point not is a user specifiable polygon. Sure this it isn't a full blown waypoint management system. But it is what supplies most the capability to GSAK under the hood.

Edited by tozainamboku
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