Support kms in haversine_distance macro (#340)

Author: bastienboutonnet

CHANGELOG.md

@@ -6,6 +6,7 @@
 * Support a new argument, `zero_length_range_allowed` in the `mutually_exclusive_ranges` test ([#307](https://github.com/fishtown-analytics/dbt-utils/pull/307) [@zemekeng](https://github.com/zemekeneng))
 * Add new schema test, `sequential_values` ([#318](https://github.com/fishtown-analytics/dbt-utils/pull/318), inspired by [@hundredwatt](https://github.com/hundredwatt))
 * Support `quarter` in the `postgres__last_day` macro ([#333](https://github.com/fishtown-analytics/dbt-utils/pull/333/files), [@seunghanhong](https://github.com/seunghanhong))
+* Add new argument, `unit`, to `haversine_distance` [#340](https://github.com/fishtown-analytics/dbt-utils/pull/340) [@bastienboutonnet](https://github.com/bastienboutonnet)
 
 
 ## Fixes

README.md

@@ -95,7 +95,7 @@ Usage:
 ---
 ### Date/Time
 #### date_spine ([source](macros/datetime/date_spine.sql))
-This macro returns the sql required to build a date spine. The spine will include the `start_date` (if it is aligned to the `datepart`), but it will not include the `end_date`. 
+This macro returns the sql required to build a date spine. The spine will include the `start_date` (if it is aligned to the `datepart`), but it will not include the `end_date`.
 
 Usage:
 ```
@@ -111,9 +111,12 @@ Usage:
 #### haversine_distance ([source](macros/geo/haversine_distance.sql))
 This macro calculates the [haversine distance](http://daynebatten.com/2015/09/latitude-longitude-distance-sql/) between a pair of x/y coordinates.
 
-Usage:
+Optionally takes a `unit` string parameter ('km' or 'mi') which defaults to miles (imperial system).
+
+**Usage:**
+
 ```
-{{ dbt_utils.haversine_distance(lat1=<float>,lon1=<float>,lat2=<float>,lon2=<float>) }}
+{{ dbt_utils.haversine_distance(lat1=<float>,lon1=<float>,lat2=<float>,lon2=<float>, unit='mi'<string>) }}
 ```
 ---
 ### Schema Tests
@@ -181,13 +184,13 @@ models:
 
 ```
 
-This macro can also be used at the column level. When this is done, the `expression` is evaluated against the column.  
+This macro can also be used at the column level. When this is done, the `expression` is evaluated against the column.
 
 ```yaml
 version: 2
-models: 
+models:
     - name: model_name
-      columns: 
+      columns:
         - name: col_a
           tests:
             - dbt_utils.expression_is_true:
@@ -197,7 +200,7 @@ models:
             - dbt_utils.expression_is_true:
                 expression: '= 1'
                 condition: col_a = 1
-      
+
 ```
 
 
@@ -361,7 +364,7 @@ models:
           upper_bound_column: ended_at
           partition_by: customer_id
           gaps: required
-  
+
   # test that each customer can have subscriptions that start and end on the same date
   - name: subscriptions
     tests:
@@ -512,9 +515,9 @@ An optional `quote_columns` parameter (`default=false`) can also be used if a co
 
 
 #### accepted_range ([source](macros/schema_tests/accepted_range.sql))
-This test checks that a column's values fall inside an expected range. Any combination of `min_value` and `max_value` is allowed, and the range can be inclusive or exclusive. Provide a `where` argument to filter to specific records only. 
+This test checks that a column's values fall inside an expected range. Any combination of `min_value` and `max_value` is allowed, and the range can be inclusive or exclusive. Provide a `where` argument to filter to specific records only.
 
-In addition to comparisons to a scalar value, you can also compare to another column's values. Any data type that supports the `>` or `<` operators can be compared, so you could also run tests like checking that all order dates are in the past. 
+In addition to comparisons to a scalar value, you can also compare to another column's values. Any data type that supports the `>` or `<` operators can be compared, so you could also run tests like checking that all order dates are in the past.
 
 Usage:
 ```yaml
@@ -528,19 +531,19 @@ models:
           - dbt_utils.accepted_range:
               min_value: 0
               inclusive: false
-      
+
       - name: account_created_at
         tests:
           - dbt_utils.accepted_range:
               max_value: "getdate()"
               #inclusive is true by default
-      
+
       - name: num_returned_orders
         tests:
           - dbt_utils.accepted_range:
               min_value: 0
               max_value: "num_orders"
-      
+
       - name: num_web_sessions
         tests:
           - dbt_utils.accepted_range:

integration_tests/data/geo/data_haversine_km.csv

@@ -0,0 +1,2 @@
+lat_1,lon_1,lat_2,lon_2,output
+48.864716,2.349014,52.379189,4.899431,430

integration_tests/data/geo/data_haversine_mi.csv

@@ -0,0 +1,2 @@
+lat_1,lon_1,lat_2,lon_2,output
+48.864716,2.349014,52.379189,4.899431,267

integration_tests/dbt_project.yml

@@ -53,8 +53,8 @@ seeds:
     sql:
       data_events_20180103:
         +schema: events
-    
+
     schema_tests:
       data_test_sequential_timestamps:
         +column_types:
-          my_timestamp: timestamp
+          my_timestamp: timestamp

integration_tests/macros/tests.sql

@@ -1,6 +1,5 @@
 
 {% macro test_assert_equal(model, actual, expected) %}
-
 select count(*) from {{ model }} where {{ actual }} != {{ expected }}
 
 {% endmacro %}

integration_tests/models/geo/schema.yml

@@ -0,0 +1,13 @@
+version: 2
+
+models:
+  - name: test_haversine_distance_km
+    tests:
+      - assert_equal:
+          actual: actual
+          expected: expected
+  - name: test_haversine_distance_mi
+    tests:
+      - assert_equal:
+          actual: actual
+          expected: expected

integration_tests/models/geo/test_haversine_distance_km.sql

@@ -0,0 +1,23 @@
+with data as (
+    select * from {{ ref('data_haversine_km') }}
+), 
+final as (
+    select
+        output as expected,
+        cast(
+            {{
+                dbt_utils.haversine_distance(
+                    lat1='lat_1', 
+                    lon1='lon_1',
+                    lat2='lat_2',
+                    lon2='lon_2',
+                    unit='km'
+                    )
+            }} as numeric
+        ) as actual
+    from data
+)
+select
+    expected,
+    round(actual,0) as actual
+from final

integration_tests/models/geo/test_haversine_distance_mi.sql

@@ -0,0 +1,39 @@
+with data as (
+    select * from {{ ref('data_haversine_mi') }}
+),
+final as (
+    select
+        output as expected,
+        cast(
+            {{
+                dbt_utils.haversine_distance(
+                    lat1='lat_1',
+                    lon1='lon_1',
+                    lat2='lat_2',
+                    lon2='lon_2',
+                    unit='mi'
+                    )
+            }} as numeric
+        ) as actual
+    from data
+
+    union all
+
+    select
+        output as expected,
+        cast(
+            {{
+                dbt_utils.haversine_distance(
+                    lat1='lat_1',
+                    lon1='lon_1',
+                    lat2='lat_2',
+                    lon2='lon_2',
+                    )
+            }} as numeric
+        ) as actual
+    from data
+)
+select
+    expected,
+    round(actual,0) as actual
+from final

macros/geo/haversine_distance.sql

@@ -3,17 +3,49 @@ This calculates the distance between two sets of latitude and longitude.
 The formula is from the following blog post:
 http://daynebatten.com/2015/09/latitude-longitude-distance-sql/
 
-The arguments should be float type. 
+The arguments should be float type.
 #}
 
-{% macro haversine_distance(lat1,lon1,lat2,lon2) -%}
-    {{ return(adapter.dispatch('haversine_distance', packages = dbt_utils._get_utils_namespaces())(lat1,lon1,lat2,lon2)) }}
+{% macro degrees_to_radians(degrees) -%}
+    acos(-1) * {{degrees}} / 180
+{%- endmacro %}
+
+{% macro haversine_distance(lat1, lon1, lat2, lon2, unit='mi') -%}
+    {{ return(adapter.dispatch('haversine_distance', packages = dbt_utils._get_utils_namespaces())(lat1,lon1,lat2,lon2,unit)) }}
 {% endmacro %}
 
-{% macro default__haversine_distance(lat1,lon1,lat2,lon2) -%}
+{% macro default__haversine_distance(lat1, lon1, lat2, lon2, unit='mi') -%}
+{%- if unit == 'mi' %}
+    {% set conversion_rate = 1 %}
+{% elif unit == 'km' %}
+    {% set conversion_rate = 1.60934 %}
+{% else %}
+    {{ exceptions.raise_compiler_error("unit input must be one of 'mi' or 'km'. Got " ~ unit) }}
+{% endif %}
 
-    2 * 3961 * asin(sqrt((sin(radians(({{lat2}} - {{lat1}}) / 2))) ^ 2 +
+    2 * 3961 * asin(sqrt(pow((sin(radians(({{ lat2 }} - {{ lat1 }}) / 2))), 2) +
     cos(radians({{lat1}})) * cos(radians({{lat2}})) *
-    (sin(radians(({{lon2}} - {{lon1}}) / 2))) ^ 2))
+    pow((sin(radians(({{ lon2 }} - {{ lon1 }}) / 2))), 2))) * {{ conversion_rate }}
+
+{%- endmacro %}
+
+
+
+{% macro bigquery__haversine_distance(lat1, lon1, lat2, lon2, unit='mi') -%}
+{% set radians_lat1 = dbt_utils.degrees_to_radians(lat1) %}
+{% set radians_lat2 = dbt_utils.degrees_to_radians(lat2) %}
+{% set radians_lon1 = dbt_utils.degrees_to_radians(lon1) %}
+{% set radians_lon2 = dbt_utils.degrees_to_radians(lon2) %}
+{%- if unit == 'mi' %}
+    {% set conversion_rate = 1 %}
+{% elif unit == 'km' %}
+    {% set conversion_rate = 1.60934 %}
+{% else %}
+    {{ exceptions.raise_compiler_error("unit input must be one of 'mi' or 'km'. Got " ~ unit) }}
+{% endif %}
+    2 * 3961 * asin(sqrt(pow(sin(({{ radians_lat2 }} - {{ radians_lat1 }}) / 2), 2) +
+    cos({{ radians_lat1 }}) * cos({{ radians_lat2 }}) *
+    pow(sin(({{ radians_lon2 }} - {{ radians_lon1 }}) / 2), 2))) * {{ conversion_rate }}
 
 {%- endmacro %}
+