Generate Statistics
Use gol query with option -f=stats to generate statistics about tag usage and relation roles. Each row in the report is a permutation of the tag values (whose keys are specified by --tags) found among the features that the query selects. The final column contains the number of features, total length or total area, based on -f:tally. For -f:tally=roles, only relations are analyzed, and the roles of their members are included in each permutation.
Formatting options:
-f:min-tally | Don’t include rows with tally less than this number/precentage |
-f:sort | Sort rows alphabetically by keys/values (instead of tally) |
-f:split-values | Treat value with semicolons as list of individual values (e.g. japanese;sushi;seafood would be treated as 3 distinct values) |
-f:tally | Statistics to generate: keys (default), tags, roles, count, length or area |
-f:unit | Length/area unit (default: m) |
Examples
Common Tags and Values
Find the most frequently-used tags (and values) for power lines in France (default -f:tally=keys):
gol query france -f=stats w[power=line]
29,098 features /key /count
=================================================
power 29,098 100.0%
= line 29,098 100.0% 100.0%
voltage 25,500 87.6%
= 63000 8,141 31.9% 28.0%
= 225000 7,410 29.1% 25.5%
= 400000 5,878 23.1% 20.2%
= 90000 3,038 11.9% 10.4%
= 20000 294 1.2% 1.0%
operator 24,089 82.8%
= RTE 22,852 94.9% 78.5%
= Enedis 355 1.5% 1.2%
cables 16,572 57.0%
= 3 13,707 82.7% 47.1%
= 6 2,167 13.1% 7.4%
= 1 542 3.3% 1.9%
...
-------------------------------------------------
76 keys with 5,602 values
Same as above, but instead organized by most common tags:
gol query france -f=stats w[power=line] -f:tally=tags
Key Value 29,098 /count
=============================================
power = * 29,098 100.0%
power = line 29,098 100.0%
voltage = * 25,500 87.6%
operator = * 24,089 82.8%
operator = RTE 22,852 78.5%
cables = * 16,572 57.0%
cables = 3 13,707 47.1%
line = * 13,060 44.9%
line = bay 8,912 30.6%
...
---------------------------------------------
76 keys 5,602 pairs 133,424 4.6/1
(4.6/1 on the total line means that, on average, there are 4.6 tags per feature)
Permutations of Tag Values
Discover the most common types of restaurants in Berlin:
gol query germany -a=berlin.poly na[amenity=restaurant]
-f=stats -f:tally=count -t=cuisine
cuisine
===========================
- 994 23.3%
italian 731 17.1%
german 288 6.7%
vietnamese 258 6.0%
...
---------------------------
Total 4,269 100.0%
Count the various forms of opening_hours for restaurants, cafes and shops, sorted by tag values. Only include opening hours that are used at least 10 times.
gol query germany na[amenity=cafe,restaurant],na[shop]
-f=stats -f:tally=count -f:min-tally=10 -f:sort=tags
-t=amenity,shop,opening_hours
amenity shop opening_hours
==================================================================
cafe - - 15,960 2.9%
restaurant - - 57,931 10.7%
- bakery - 19,059 3.5%
- butcher - 7,332 1.4%
...
- supermarket Mo-Sa 07:00-20:00 2,843 0.5%
- supermarket Mo-Sa 08:00-20:00 2,804 0.5%
...
------------------------------------------------------------------
Total 541,833 100.0%
Length and Area
Calculate the total length (in kilometers) of all road-like features in France, broken out by highway type:
gol query world -a=france.poly w[highway] -f=stats -t=highway -f:tally=length -f:unit=km
highway
===================================
track 647,966 km 29.2%
unclassified 464,661 km 20.9%
tertiary 243,117 km 10.9%
residential 239,686 km 10.8%
...
-----------------------------------
Total 2,221,737 km 100.0%
Measure the areas of different types of land use (excluding forests and farmland):
gol query world a[landuse != forest,farmland] -f=stats -t=landuse -f:tally=area
landuse
----------------------------
residential 240,312,392 m2
commercial 80,900,121 m2
...
Roles
Analyze how often certain roles appear in route relations:
gol query world r[route] -f=stats -t=route -f:tally=roles
route Role Members in Relations
=========================================================
bus (empty) 5,052,780 in 36,352 44.8%
hiking (empty) 1,450,043 in 33,066 12.9%
bicycle (empty) 1,166,304 in 19,062 10.3%
bus stop 585,931 in 33,370 5.2%
bus platform 574,225 in 31,602 5.1%
...
---------------------------------------------------------
Total 11,274,462 in 122,155 100.0%
Formatting Options
-f:max-width=<NUMBER>
The maximum width (in characters) of the displayed table (used by stats and table). Default: 100
-f:min-tally=<NUMBER>|<PERCENTAGE>
Omits rows in the report whose subtotal (number of features, length or area) is less than the specified number (or less than the specified percentage of the total). Default: 1%
-f:sort=<KEYS>|tags|tally
Sorts rows alphabetically by key/value instead of tally.
-f:split-values
Splits up values that contain semicolons and tallies the items individually. For example, cuisine=japanese;sushi;seafood would generate three separate tallies for the cuisine tag.
-f:tally=<OPTION>
What the report should calculate:
area | the total area of all features in each group |
count | the number of features in each group (default) |
keys | the keys used by the selected features, as well as their most common values |
length | the total length of all features in each group |
roles | the roles of the relations in each group (total number of members for each role, and count of relations in which the role is used) |
tags | the tags used by the selected features |
-f:unit=<OPTION>
The length/area unit to use for -f:tally=length and -f:tally=area:
m | (square) meters (default) |
km | (square) kilometers |
ft | (square) feet |
yd | (square) yards |
ha | hectares |
ac | acres |