Function Definition

mygps66iaccuracy[] takes two arguments. The first argument is a single list containing measurements with each measurement being of the form:
{{YYYY,m,d,h,m,s},{±DD.DDD,±DD.DDDDD}}. The second argument is the accuracy in feet.
​
An example containing 10 measurements:
​
samptrack={{{2022,6,10,17,52,43.},{38.9374,-771929}},{{2022,6,10,17,52,44.},{38.9374,-771929}},{{2022,6,10,17,53,10.},{38.9374,-771929}},{{2022,6,10,17,53,18.},{38.9374,-771929}},{{2022,6,10,17,53,36.},{38.9374,-771929}},{{2022,6,10,17,54,53.},{38.9374,-771929}},{{2022,6,10,17,58,52.},{38.9375,-77193}},{{2022,6,10,18,1,48.},{38.9375,-77193}},{{2022,6,10,18,4,31.},{38.9374,-771929}},{{2022,6,10,18,4,54.},{38.9374,-771929}}}a
​
Here is an example of those 10 measurements, 7 of which are within 10 feet horizontally of the average location:
In[]:=
mygps66iaccuracy[samptrack,10]
Out[]=
7
10
In the results I posted on the Garmin forum, I used Excel’s find/replace to clean up the data from the GPS receiver. If you do the same, keep in mind that the coordinates have to be numbers and not text.
In[]:=
list=Import["C:\\Users\\jay\\OneDrive\\Desktop\\To be Inserted then Discarded\\test1a.xls"];​​list=list[[1]];​​list2=Table[{list[[i,1]],{list[[i,2]],list[[i,3]]}},{i,1,Length[list]}];​​N[mygps66iaccuracy[list2,13.1234]]
{
20.073
ft
,
14.2896
ft
,
17.889
ft
,
25.072
ft
,
22.4507
ft
,
13.6971
ft
,
3.93678
ft
,
7.20963
ft
,
7.61889
ft
,
7.20963
ft
,
9.23887
ft
,
15.0258
ft
,
15.0258
ft
,
10.4849
ft
,
6.23916
ft
,
3.23125
ft
,
2.35564
ft
,
6.84992
ft
,
4.64403
ft
,
3.40849
ft
,
5.17587
ft
,
14.7633
ft
,
8.44471
ft
,
21.8613
ft
,
14.2053
ft
,
14.2053
ft
,
16.6628
ft
,
14.2053
ft
,
7.45044
ft
,
8.44471
ft
,
8.44471
ft
,
9.93088
ft
}
Out[]=
0.5625
dists={
20.07298640407522`
ft
,
14.289619552102014`
ft
,
17.888957566184562`
ft
,
25.07202212429499`
ft
,
22.45065387436929`
ft
,
13.697124436332977`
ft
,
3.9367819203266965`
ft
,
7.209627451137802`
ft
,
7.618888977709916`
ft
,
7.209627451137802`
ft
,
9.238874671891402`
ft
,
15.025779320658383`
ft
,
15.025779320658383`
ft
,
10.484902166610551`
ft
,
6.239158455591217`
ft
,
3.231248700948196`
ft
,
2.3556380408265203`
ft
,
6.849922886089605`
ft
,
4.644027600584367`
ft
,
3.4084850226190744`
ft
,
5.175868918429864`
ft
,
14.76329622917466`
ft
,
8.444707855110641`
ft
,
21.861347867043264`
ft
,
14.205314344921383`
ft
,
14.205314344921383`
ft
,
16.662838278188158`
ft
,
14.205314344921383`
ft
,
7.450444780196757`
ft
,
8.444707855110641`
ft
,
8.444707855110641`
ft
,
9.930881698846953`
ft
};
In[]:=
StandardDeviation[dists]
Out[]=
6.05417
ft