Count with nearstat

[Mario Marra]

Hi all,
My dataset is made up of gasoline stations located by latitude and longitude. These stations are divided into different brands.

I was able to count how many stations there are between zero and one kilometre for each station using:

nearstat latitudine longitudine, near(latitudine longitudine)  distvar(distnn1) ncount(nn_01) dband(0 1) replace

Now I should count how many stations there are belonging to a particular brand between zero and one kilometre for every single station.
For example: take the first station, Q8. How many Shell stations are there close to Q8 between zero and one kilometre?
take the second station, Tamoil. How many Shell stations are there close to Tamoil between zero and one kilometre?
and so on for every station in my dataset.

I tried to insert the "if" operator but I get the same result as before.

nearstat latitudine longitudine if Shell==1, near(latitudine longitudine)  distvar(distnn1) ncount(nn_01) dband(0 1) replace

Does anyone know how to do it?

Thanks in advance.

Mario

[Mario Marra]

I post here a small piece of my dataset

* Example generated by -dataex-. To install: ssc install dataex
clear
input long idimpianto str22 bandiera float(latitudine longitudine)
17169 "Repsol"    41.91485 12.463936
21227 "Tamoil"    41.89114 12.502335
 9893 "Agip Eni"  41.87744  12.47566
15691 "Q8"        41.90972 12.451632
30852 "Api-Ip"     41.9213 12.460135
14017 "Api-Ip"    41.90893 12.492738
16793 "Agip Eni"  41.91527 12.469448
13832 "Agip Eni"  41.92608 12.457652
 9580 "Agip Eni"  41.89259    12.508
20188 "Api-Ip"    41.91012 12.474128
12185 "Agip Eni"   41.9104   12.4465
19955 "Agip Eni"  41.89331 12.488094
18204 "Api-Ip"    41.90123 12.504909
16807 "Agip Eni"  41.88868 12.478415
16854 "Agip Eni"  41.87151  12.49283
17108 "Api-Ip"    41.90509  12.46026
18523 "Q8"        41.91019 12.474433
28514 "Api-Ip"    41.88104 12.484383
16769 "Api-Ip"    41.91599  12.45428
20893 "Total Erg" 41.93837 12.537647
17837 "Api-Ip"    41.91119 12.444272
22288 "Retitalia" 41.90407 12.446028
11812 "Q8"        41.94366 12.537134
 4864 "Agip Eni"  42.01099 12.517746
17955 "Api-Ip"    41.91938 12.473583
end

where "idimpianto" is the unique number that identifies gasoline station and "bandiera" is station brand

* Count how many stations there are between zero and one kilometre for each station
nearstat latitudine longitudine, near(latitudine longitudine) distvar(distnn1) ncount(nn_01) dband(0 1) replace

* how many Agip Eni are there in a kilometer for each station? using 

	
	
 if
 operator
nearstat latitudine longitudine if bandiera=="Agip Eni", near(latitudine longitudine)  distvar(distnn_eni1) ncount(nn_eni_01) dband(0 1) replace

[Nick Cox]

Also posted on https://stackoverflow.com/questions/...rstat-in-stata

[Justin Niakamal]

I'm not familiar with nearstat, but I think you should look into geonear. You'll get a combination of all neighbors and then you should be able to do the qualifiers/tabulations from there.

Note geonear is from SSC and written by Robert Picard.

[Andrew Musau]

Going with Justin Blasongame's advice, here is one way:

* Example generated by -dataex-. To install: ssc install dataex
clear
input long idimpianto str22 bandiera float(latitudine longitudine)
17169 "Repsol"    41.91485 12.463936
21227 "Tamoil"    41.89114 12.502335
 9893 "Agip Eni"  41.87744  12.47566
15691 "Q8"        41.90972 12.451632
30852 "Api-Ip"     41.9213 12.460135
14017 "Api-Ip"    41.90893 12.492738
16793 "Agip Eni"  41.91527 12.469448
13832 "Agip Eni"  41.92608 12.457652
 9580 "Agip Eni"  41.89259    12.508
20188 "Api-Ip"    41.91012 12.474128
12185 "Agip Eni"   41.9104   12.4465
19955 "Agip Eni"  41.89331 12.488094
18204 "Api-Ip"    41.90123 12.504909
16807 "Agip Eni"  41.88868 12.478415
16854 "Agip Eni"  41.87151  12.49283
17108 "Api-Ip"    41.90509  12.46026
18523 "Q8"        41.91019 12.474433
28514 "Api-Ip"    41.88104 12.484383
16769 "Api-Ip"    41.91599  12.45428
20893 "Total Erg" 41.93837 12.537647
17837 "Api-Ip"    41.91119 12.444272
22288 "Retitalia" 41.90407 12.446028
11812 "Q8"        41.94366 12.537134
 4864 "Agip Eni"  42.01099 12.517746
17955 "Api-Ip"    41.91938 12.473583
end
*ssc install geonear
tempfile gas_stations names names2
preserve
rename (idimpianto latitudine longitudine) (nid nlat nlon)
save `gas_stations', replace
keep nid bandiera
save `names', replace
rename (nid bandiera) (idimpianto name)
save `names2', replace
restore
*ALL GAS STATIONS WITHIN 1 KM
geonear id lat lon using "`gas_stations'", n( nid nlat nlon) ign long within(1) near(0)
merge m:1 nid using `names', keep(master match) nogen
merge m:1 idimpianto using `names2', keep(master match) nogen
order idimpianto name nid bandiera  
*TOTAL NUMBER - ALL GAS STATIONS
bys idimpianto: egen total= count(nid)
*TOTAL NUMBER AGIP-ENI
bys idimpianto: egen Agip_Eni= total( bandiera== "Agip Eni")

Res.:

. l, sepby(id)

     +-------------------------------------------------------------------------+
     | idimpi~o        name     nid    bandiera   km_to_nid   total   Agip_Eni |
     |-------------------------------------------------------------------------|
  1. |     9580    Agip Eni   18204      Api-Ip   .99425279       2          0 |
  2. |     9580    Agip Eni   21227      Tamoil   .49590694       2          0 |
     |-------------------------------------------------------------------------|
  3. |     9893    Agip Eni   28514      Api-Ip   .82550686       1          0 |
     |-------------------------------------------------------------------------|
  4. |    11812          Q8   20893   Total Erg   .58985922       1          0 |
     |-------------------------------------------------------------------------|
  5. |    12185    Agip Eni   17837      Api-Ip   .20419082       4          0 |
  6. |    12185    Agip Eni   15691          Q8   .43131316       4          0 |
  7. |    12185    Agip Eni   22288   Retitalia   .70478981       4          0 |
  8. |    12185    Agip Eni   16769      Api-Ip    .8947647       4          0 |
     |-------------------------------------------------------------------------|
  9. |    13832    Agip Eni   30852      Api-Ip   .56982039       1          0 |
     |-------------------------------------------------------------------------|
 10. |    15691          Q8   17108      Api-Ip   .88038104       5          1 |
 11. |    15691          Q8   22288   Retitalia   .78082912       5          1 |
 12. |    15691          Q8   16769      Api-Ip   .73056183       5          1 |
 13. |    15691          Q8   12185    Agip Eni   .43131316       5          1 |
 14. |    15691          Q8   17837      Api-Ip   .63051576       5          1 |
     |-------------------------------------------------------------------------|
 15. |    16769      Api-Ip   12185    Agip Eni    .8947647       5          1 |
 16. |    16769      Api-Ip   15691          Q8   .73056183       5          1 |
 17. |    16769      Api-Ip   17169      Repsol   .80897278       5          1 |
 18. |    16769      Api-Ip   30852      Api-Ip   .76377999       5          1 |
 19. |    16769      Api-Ip   17837      Api-Ip   .98514433       5          1 |
     |-------------------------------------------------------------------------|
 20. |    16793    Agip Eni   20188      Api-Ip   .69162537       4          0 |
 21. |    16793    Agip Eni   17169      Repsol   .45852914       4          0 |
 22. |    16793    Agip Eni   18523          Q8   .69954855       4          0 |
 23. |    16793    Agip Eni   17955      Api-Ip   .57075678       4          0 |
     |-------------------------------------------------------------------------|
 24. |    16807    Agip Eni   28514      Api-Ip   .98282863       2          1 |
 25. |    16807    Agip Eni   19955    Agip Eni   .95245506       2          1 |
     |-------------------------------------------------------------------------|
 26. |    17108      Api-Ip   15691          Q8   .88038104       1          0 |
     |-------------------------------------------------------------------------|
 27. |    17169      Repsol   17955      Api-Ip   .94399078       5          1 |
 28. |    17169      Repsol   16793    Agip Eni   .45852914       5          1 |
 29. |    17169      Repsol   16769      Api-Ip   .80897278       5          1 |
 30. |    17169      Repsol   30852      Api-Ip   .78317707       5          1 |
 31. |    17169      Repsol   20188      Api-Ip   .99393177       5          1 |
     |-------------------------------------------------------------------------|
 32. |    17837      Api-Ip   15691          Q8   .63051576       4          1 |
 33. |    17837      Api-Ip   16769      Api-Ip   .98514433       4          1 |
 34. |    17837      Api-Ip   12185    Agip Eni   .20419082       4          1 |
 35. |    17837      Api-Ip   22288   Retitalia   .80473515       4          1 |
     |-------------------------------------------------------------------------|
 36. |    17955      Api-Ip   16793    Agip Eni   .57075678       2          1 |
 37. |    17955      Api-Ip   17169      Repsol   .94399078       2          1 |
     |-------------------------------------------------------------------------|
 38. |    18204      Api-Ip    9580    Agip Eni   .99425279       1          1 |
     |-------------------------------------------------------------------------|
 39. |    18523          Q8   16793    Agip Eni   .69954855       2          1 |
 40. |    18523          Q8   20188      Api-Ip   .02650829       2          1 |
     |-------------------------------------------------------------------------|
 41. |    19955    Agip Eni   16807    Agip Eni   .95245506       1          1 |
     |-------------------------------------------------------------------------|
 42. |    20188      Api-Ip   17169      Repsol   .99393177       3          1 |
 43. |    20188      Api-Ip   16793    Agip Eni   .69162537       3          1 |
 44. |    20188      Api-Ip   18523          Q8   .02650829       3          1 |
     |-------------------------------------------------------------------------|
 45. |    20893   Total Erg   11812          Q8   .58985922       1          0 |
     |-------------------------------------------------------------------------|
 46. |    21227      Tamoil    9580    Agip Eni   .49590694       1          1 |
     |-------------------------------------------------------------------------|
 47. |    22288   Retitalia   15691          Q8   .78082912       3          1 |
 48. |    22288   Retitalia   12185    Agip Eni   .70478981       3          1 |
 49. |    22288   Retitalia   17837      Api-Ip   .80473515       3          1 |
     |-------------------------------------------------------------------------|
 50. |    28514      Api-Ip    9893    Agip Eni   .82550686       2          2 |
 51. |    28514      Api-Ip   16807    Agip Eni   .98282863       2          2 |
     |-------------------------------------------------------------------------|
 52. |    30852      Api-Ip   16769      Api-Ip   .76377999       3          1 |
 53. |    30852      Api-Ip   13832    Agip Eni   .56982039       3          1 |
 54. |    30852      Api-Ip   17169      Repsol   .78317707       3          1 |
     +-------------------------------------------------------------------------+

.