Jump to content

position format changed.


Recommended Posts

10 hours ago, Capt. Bob said:

When Geocaching only three decimal places are necessary.   So why show four decimal places?  It is to show the confidence level of the third decimal place.  So, for example, using the latitude from above 42° 33.86755988’ should the minutes be displayed as 33.867 or 33.868 or 33.8675?  With only three decimal places the user can assume the unit rounds up the last decimal place but the user can’t be sure. By showing four decimal places the user is confident of the third decimal place.  (This is a good policy when selling your product internationally.)

 

When the Oregon 700 still showed just three decimal places, it was rounding to nearest. In other words, it was doing automatically what you're now doing manually.

Link to comment
6 hours ago, Megalodon said:

 do not want to use the 4 digits, because I have to take care of two more numbers when entering a coordinate.

Garmin offers it in the configuration and so they should implement it and now fix it, that's all I expect.

 

The 4th decimal place, as it applies to selecting 3 decimal places, seems to be a bug, and maybe it will be addressed in an update.  I'd prefer the exact same display that Geocaching.com has.  Today, when entering coords, having to deal with the extra decimal just slows me down.  I could in theory zoom all the way into the Garmin's map and I'd see the point in its precise spot out to 4 decimal places, but for Geocaching purposes, it's not necessary.

  • Upvote 1
Link to comment
11 hours ago, ecanderson said:

@Capt. Bob

42 33.868 works for me.  Round it up or down (up, using the classic method for your example).  It's all of the information I could possibly believe in the field.  Give or take +/- 4 feet (0.001) at my latitude is typically more accuracy than I can hope for in any case.  I am NOT 'confident' of the third decimal place in any practical sense.

 

 

I agree with you that three decimal places are sufficient for most non-professional uses.  However, if your GPSr has a built in accuracy error of a 4 foot radius (search area = π* 4^2 = 50 sq. ft.) that’s good, but in reality you don’t.  Suppose the CO uses the same GPSr as yours then the placement error could possibly be a combined 8 foot radius error (search area = π* 8^2 = 201 sq. ft.).   However, we use an X-Y coordinate system so an 8 foot radius becomes a square with 16 foot sides (search area = 16 x 16 = 256 sq. ft. or 5 times larger than first thought).

Link to comment

Three decimal places are going to have to be sufficient for ANY non-governmental use unless you have a DGPS system in place on the ground that provides any further useful digits. 

 

Further, my GPS does not have an "accuracy error" of 4 feet (which I should have called 6', as I now note that those digits in the prior example were part of a latitude, not longitude).  It has a precision limit of 0.001 that is less than the accuracy limit, a larger number.  The computed position, expressed in 3 decimal minutes, is less accurate than the precision of the three decimal minutes being used to represent it.

 

To be more clear about it at this latitude, we have a box whose limitation in precision is about 4 feet E/W x 6 feet N/S.  The precision error is not double that -- it's the truncation or rounding error (we don't have any insight as to which it is).  Using the same example, if you start with 42° 33.86755988, it's either truncated to 42° 33.867 or rounded down to 42° 33.867 or rounded up to 42° 33.868.  The variability is only 0.001 in any of those cases.

 

Since the size of that box is substantially less than the likely error in the fix to begin with, we have no need know what the 4th digit is after the decimal.  As I say, I can therefore live very comfortably with a precision down to only 0.001 since that's already tighter than the accuracy is likely to be at any given moment.

 

 

Edited by ecanderson
Some annoying typos.
  • Upvote 1
Link to comment

Moderator note: this thread has devolved into bickering and just short of name-calling.  Garmin made the change you are stressing out about. Lobbying this site to change something that's useful to a small percentage of their users is unlikely to be productive. Actually, lobbing THIS group specifically is highly unlikely to be effective; nobody reading here can grant your wish so you should make your request to Groundspeak if you want the site changed. But I'd wager they're going to push this back onto Garmin because this site really doesn't need device-specific code in these paths.

So. Please stop the bickering here. Redirect your feature request to Garmin to have them remove this feature.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...