There are multiple tools in the GeoAnalytics Tools toolbox that allow you to apply an expression.
 Buffer expressions in Create Buffers
 Buffer expressions in Reconstruct Tracks
 Join conditions in Join Features
 Incident conditions in Detect Incidents
 Calculating field values in Calculate Field
GeoAnalytics Tools that use expressions have different usages, as well limitations on which expressions can be applied. At 11.2, all expressions used in ArcGIS GeoAnalytics Server support Arcade.
Learn more about Arcade functions
Expressions in Detect Incidents
Expressions are used in the Detect Incidents tool to specify start and end conditions for incidents. A Detect Incidents condition must always result in true or false. Use a condition to check if a feature should be included in an incident. The conditions are tested against each feature to determine which features are incidents. Calculations are performed when the analysis runs on your ArcGIS GeoAnalytics Server. Expression examples that you can use are included in the sections below.
Mathematical operator and function examples
Expressions can mathematically process numbers. The following table shows a sample of available operations.
Learn more about mathematical operations and functions available in Arcade
Operator  Explanation  Example  Result 

a + b  a plus b.  fieldname contains a value of 1.5. $feature["fieldname"] + 2.5  4.0 
a  b  a minus b.  fieldname contains a value of 3.3. $feature["fieldname"] 2.2  1.1 
a * b  a times b.  fieldname contains a value of 2.0. $feature["fieldname"] * 2.2  4.4 
a / b  a divided by b.  fieldname contains a value of 4.0. $feature["fieldname"] / 1.25  3.2 
abs( a )  Returns the absolute (positive) value of a.  fieldname contains a value of 1.5. abs($feature["fieldname"])  1.5 
log( a )  Returns the natural logarithm (base E) of a.  fieldname contains a value of 1. log($feature["fieldname"])  0 
sin( a )  Returns the trigonometric sine of a. The input is assumed to be an angle in radians.  fieldname contains a value of 1.5707. sin($feature["fieldname"])  1 
cos( a )  Returns the trigonometric cosine of a. The input is assumed to be an angle in radians.  fieldname contains a value of 0. cos($feature["fieldname"])  1 
tan( a )  Returns the tangent of a. The input is assumed to be an angle in radians.  fieldname contains a value of 0. tan($feature["fieldname"])  0 
sqrt( a )  Returns the square root of a.  fieldname contains a value of 9. sqrt($feature["fieldname"])  3 
min( a, b )  Returns the lowestvalued number between a and b.  fieldname contains a value of 1.5 and a value of 3. min($feature["fieldname"], 3)  3 
max( a, b )  Returns the highestvalued number between a and b.  fieldname1 contains a value of 1.5, and fieldname2 contains a value of 3. max($feature["fieldname1"], $feature["fieldname2"])  1.5 
constrain(<value>,<low>,<high>)  Returns the input value if it's within the constraining bounds. If the input value is less than the low value, it returns the low value. If the input value is greater than the high value, it returns the high value.  constrain($feature["distance"], 0, 10) constrain($feature['Store dist'], 6, distance)  Returns 0 if distance is less than 0, 10 if distance is greater than 10, and distance otherwise. Returns 6 if Store dist is less than 6, distance if Store dist is greater than distance, and Store dist otherwise. 
Multiplication example for a condition detecting an incident.
$feature["Distance"] * 2 > 50
Text function examples
Detect Incidents expressions can process text. The following table shows a sample of available operations.
Learn more about text functions available in Arcade
Operator  Explanation  Example  Result 

concatenate( <values>, <separator>)  Concatenates values together and returns a string.
 fieldname contains a value of GeoAnalytics. Concatenate ([$features["fieldname"], "is", "great!"], ' ')  GeoAnalytics is great! 
find(<searchText>, <text>, <startPos>)  Finds a string within a string. Wildcards are not supported.
 fieldname1 contains a value of 14NorthStreet and fieldname2 contains a value of North. find($feature["fieldname2"], $feature["fieldname1"])  2 
lower(<value>)  Makes a string lowercase.
 fieldname contains a value of GEOANALYTICS. lower($feature["fieldname"])  geoanalytics 
Text example using find and lower.
find(("north"), lower("146NorthStreet")) == 2
Date function examples
You can use Detect Incidents from expressions that use dates. The following table shows a sample of available operations.
Learn more about date functions available in Arcade
In Arcade, month values range from 0 (January) to 11 (December), days from 1 to 31, hours from 0 (12:00 a.m.) to 23 (11:00 p.m.), minutes and seconds from 0 to 59, and milliseconds from 0 to 999. Arcade dates return time values in the location of your GeoAnalytics Server.
Operator  Explanation  Example  Result 

date( <value>, <month>, <day>, <hour>, <minute>)  Parses a value or set of values into a date string.
 fieldname contains a value of 1476987783555. Example 1: Date($features["fieldname"]) Example 2: Date(2017,0,14,0) Example 3: Date()  Example 1: 20 Oct 2016 11:23:03 am Example 2: 14 Jan 2017 12:00:00 am Example 3: Returns the current time 
DateDiff(<date1>, <date2>, <units>)  Subtracts two dates and returns the difference in the specified units.
 Example 1: DateDiff(Date(2017,1,14,0), Date()) Example 2: DateDiff(Date(2017,1,14,0), Date(), "Years")  Result will vary depending on when you run this command. Example 1: 20532129137 Example 2: 0.6546783768647119 
Year(<dateValue>)  Returns the year of the given date.
 Example 1: fieldname is a field of type Date with a value of 09 Oct 2017 04:30:43 pm. Year($feature["fieldname"]) Example 2: fieldname is a string field formatted as an ISO 8601 string with a value of 20120927.  Example 1: 2017 Example 2: 2012 
Conditional operators
Conditional statements can use the following operators:
Operator  Explanation  Example  Results 

a > b a < b  a is greater than b a is less than b  10 > 2  False 
a >= b a <= b  a is greater than or equal to b a is less than or equal to b  abs(10) >= 10  True 
a != b  a is not equal to b  abs(3) != 3  True 
a == b  a is equal to b  abs(5) == 5  True 
<condition1>  <condition2>  Condition 1 or condition 2 is met.  (abs(5) == 5)  (10 < 2)  True 
<condition1> && <condition2>  Condition 1 and condition 2 are met.  (abs(5) == 5) && (10 < 2)  False 
Logical operator examples
In addition to the conditional operators, you can use more advanced logical operators with Detect Incidents.
Learn more about logical functions available in Arcade
Function  Explanation  Example  Result 

iif(<condition>,<true value>,<false value>)  Returns one value if a condition evaluates to true, and another value if the condition evaluates to false. <true value> and <false value> can be the following:
 iif($feature["field1"] > $feature["field2"], $feature["field1"], 0) iif($feature["field1"] > $feature["field2"], iif($feature["field2"] = 0, $feature["field3"], $feature["field4"]), 0)  Returns field1 if field1 is greater than field2, and 0 otherwise. Returns the result of the second iif function if field1 is greater than field2, and 0 otherwise. 
when(<expression1> , <result1> , <expression2> , <result2> , ... , <expressionN> , <resultN>, <default>)  Evaluates a series of expressions in turn until one evaluates to true.
 when(($feature["field1"] + 10) > 1, 1,($feature["field2"] + 10) > 2 , 2, $feature["field3"])  If field1 + 10 is greater than 1, it returns 1. If not, it checks if field2 + 10 is greater than 2. If it is, it returns 2. If not, it returns field3. 
decode(<conditional val> , <case1> , <result1>, <case2>, <result2>, ... <caseN>, <resultN>, <defaultValue> )  The decode function evaluates an expression and compares its value with subsequent parameters. If the expression matches, it returns the next parameter value. If none match, there is the option for the last parameter to be a default return value.
 decode($feature["field1"] + 3 , $feature["field1"], 1, $feature["field2"], 2, 0)  Compares equality between the conditional val field1 + 3 and case1 field1. If true, it returns 1. If false, it compares the equality between field1 + 3 and field2. If true, it returns 2; otherwise, it returns 0. 
Trackaware examples
In addition, some GeoAnalytics Tools, such as Detect Incidents and Calculate Field, can use trackaware equations in Arcade.
Function  Explanation  Example  Result  

TrackStartTime()  Calculates the start time of a track in milliseconds from epoch.  Using a track that starts on January 2, 2017. TrackStartTime()  1483315200000  
TrackDuration()  Calculates the duration of a track in milliseconds from the start until the current time step.  Using a track that starts on January 2, 2017, and the current time is January 4, 2017. TrackDuration()  172800000  
TrackCurrentTime()  Calculates the current time in a track.  Using a feature that occurs on January 3, 2017, at 9:00 a.m. TrackCurrentTime()  1483434000000  
TrackIndex  Returns the time index of the feature being calculated.  Calculating this value on the first feature in a track. TrackIndex  0  
TrackFieldWindow(<fieldName>, <startIndex>, <endIndex>)  Returns an array of values in the given field for the specified time index. The window function allows you to go forward and backward in time. The expression is evaluated at each feature in the track.
 MyField has sequentially ordered values of [10, 20, 30, 40, 50]. The expression is evaluated at each feature in the track. Results are returned inclusive of the start feature, and exclusive of the end feature. Example 1: TrackFieldWindow("MyField,1,2) Example 2: TrackFieldWindow("MyField,2,0)[0] Example 3: TrackFieldWindow("MyField,0,3)[2]  Example 1: When evaluated at each feature, the table shows the following results:
Example 2: When evaluated at index 2 (value is 30), it returns 10. Example 3: When evaluated at index 2 (value is 30), it returns 50.  
TrackGeometryWindow(<startIndex>, <endIndex>)  Returns an array of values representing geometry for the specified time index. The window function allows you to go forward and backward in time. The expression is evaluated at each feature in the track.
 MyField has sequentially ordered values of [10, 20, 30, 40, 50]. The geometry of the features is [{x: 1, y: 1},{x: 2, y: 2} ,{x: null, y: null},{x: 4, y: 4}, {x: 5, y: 5}]. The expression is evaluated at each feature in the track. Results are returned inclusive of the start feature, and exclusive of the end feature. Example 1: TrackGeometryWindow(1,2) Example 2: TrackGeometryWindow(0,1)[0] on a polyline dataset Example 3: TrackGeometryWindow(0,1)[0] on a polygon dataset Example 4: Find the X value of the previous point TrackGeometryWindow(1,0)[0]["x"]  Example 1: When evaluated at each feature, the table shows the following results:
Example 2: Polylines are returned in the following format: [{"paths":[[[180,22.88],[177.6,23.6]],[[180,18.099999999999994],[179.7,18.4],[179.4,18.7],[178.9,18.9],[178.5,19.3],[178.2,19.7],[178.4,20],[178.8,20.2],[178.9,21.8],[179,22.2],[179.4,22.7],[180,22.88]],[[178,17],[178.8,17.3],[179.2,17.5],[179.6,17.8],[179.9,18],[180,18.099999999999994]]]}] Example 3: Polygons are returned in the following format: [{"rings":[[[7882559.1197999995,6376090.883500002],[7893142.474300001,6042715.216800004],[8544018.775999999,6045361.0554000065],[8544018.775999999,6376090.883500002],[7882559.1197999995,6376090.883500002]]]}] Example 4: Evaluated at index 2 (value is 30): 2  
TrackWindow(<value1>, <value2>)  Returns an array of values representing geometry and all attributes for the specified time index. The window function allows you to go forward and backward in time.
 MyField has sequentially ordered values of [10, 20, 30, 40, 50], in addition to the objectID, globalID and instant_datetime fields. The geometry of the features is [{x: 1, y: 1},{x: 2, y: 2} ,{x: null, y: null},{x: 4, y: 4}, {x: 5, y: 5}]. The expression is evaluated at each feature in the track. Results are returned inclusive of the start feature, and exclusive of the end feature. Example 1: TrackWindow(1,0)[0] Example 2: geometry(TrackWindow(1,0)[0]["x"]  Example 1: When evaluated at each feature, the table shows the following results:
Example 2: Evaluated at index 2 (value is 30): 2 
Use the following track expressions to calculate distance, speed, and acceleration on tracks.
All distance calculations are calculated in meters, speed in meters per second, and acceleration in meters per second squared. Distances are measured using geodesic distances.
Function  Explanation 

TrackCurrentDistance()  The sum of the distances travelled between observations from the first to the current observation. 
TrackDistanceAt(value)  The sum of the distances travelled between observations from the first to the current observation plus the given value. 
TrackDistanceWindow(value1, value2)  The distances between the first (inclusive) to the last value (exclusive) in a window about the current observation (0). 
TrackCurrentSpeed()  The speed between the previous observation and the current observation. 
TrackSpeedAt(value1)  The speed at the observation relative to the current observation. For example, at value 2, it's the speed at the observation two observations after the current observation. 
TrackSpeedWindow(value1, value2)  The speed values between the first (inclusive) and the last value (exclusive) in a window around the current observation (0). 
TrackCurrentAcceleration()  The acceleration between the previous observation and the current observation. 
TrackAccelerationAt(value1)  The acceleration at the observation relative to the current observation. 
TrackAccelerationWindow(value1, value2)  The acceleration values between the first (inclusive) to the last value (exclusive) in a window around the current observation (0). 
The example calculations for distance, speed, and acceleration will use examples from the following image:
Function  Example result  

TrackCurrentDistance() 
 
TrackDistanceAt(2) 
 
TrackDistanceWindow(1, 2) 
 
TrackCurrentSpeed() 
 
TrackSpeedAt(2) 
 
TrackSpeedWindow(1, 2) 
 
TrackCurrentAcceleration() 
 
TrackAccelerationAt(2) 
 
TrackAccelerationWindow(1, 2) 
