Buffer expression examples for ArcGIS Enterprise 10.5 and 10.5.1

Entering values or using a field are not the only way you can specify the size of a buffer using GeoAnalytics Tools. In some cases, you might want to perform a mathematical calculation to set the buffer size. You can perform simple as well as advanced calculations that are applied to all records. This calculation is applied to each feature. The sections below include examples of using a buffer expression. Calculations are performed when analysis is run on your ArcGIS GeoAnalytics Server.

At ArcGIS Enterprise 10.6 and later, expressions are formatted using Arcade Expressions. Learn more about Arcade expressions and about Arcade Expressions with GeoAnalytics Server and 10.6 and later.

Buffer expressions are used by the Reconstruct Tracks and Create Buffers tools.

Simple calculations

Simple math examples

Buffer expressions are able to mathematically process numbers.


Operator	Explanation	Example	Result
a + b	a plus b	`fieldname` contains a value of 1.5 ["fieldname"] + 2.5	4.0
a - b	a minus b	`fieldname` contains a value of 3.3 ["fieldname"]- 2.2	1.1
a * b	a multiplied by b	`fieldname` contains a value of 2.0 ["fieldname"] * 2.2	4.4
a / b	a divided by b	`fieldname` contains a value of 4.0 ["fieldname"] / 1.25	3.2
abs( a )	Returns the absolute (positive) value of a.	`fieldname` contains a value of -1.5 abs(["fieldname"])	1.5
log ( a )	Returns the natural logarithm (base E) of a.	`fieldname` contains a value of 1 log(["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(["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(["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(["fieldname"])	0
sqrt( a )	Returns the square root of a.	`fieldname` contains a value of 9 sqrt(["fieldname"])	3
min( a, b )	Returns the lowest valued number between a and b.	`fieldname` contains a value of 1.5, and a value of -3 min(["fieldname"], -3)	-3
max( a, b )	Returns the highest valued number between a or b.	`fieldname1` contains a value of 1.5, and `fieldname2` contains a value of -3 max(["fieldname1"], ["fieldname2"])	1.5

Multiplication

["Distance"] * 2

Built-in functions for GeoAnalytics Tools

As distance function examples

Buffer expressions are able to cast numeric values to a linear distance.


Function	Explanation	Example	Result
as_meters( <value> )	Applies a calculation assuming the input values are in meters	as_meters( ["fieldname"] ) as_meters(150)	Results are buffered by 150 meters.
as_kilometers( <value> )	Applies a calculation assuming the input values are in kilometers	as_kilometers( ["fieldname"] ) as_kilometers(150)	Results are buffered by 150 kilometers.
as_feet( <value> )	Applies a calculation assuming the input values are in feet	as_feet( ["fieldname"] ) as_feet(150)	Results are buffered by 150 feet.
as_yards( <value> )	Applies a calculation assuming the input values are in yards	as_yards( ["fieldname"] ) as_yards(150)	Results are buffered by 150 yards.
as_nautical_miles( <value> )	Applies a calculation assuming the input values are in nautical miles	as_nautical_miles( ["fieldname"] ) as_nautical_miles(150)	Results are buffered by 150 nautical miles.
as_miles( <value> )	Applies a calculation assuming the input values are in miles	as_miles( ["fieldname"] ) as_miles(150)	Results are buffered by 150 miles.

For each feature, multiply the field Distance assuming it's in kilometers, and add 10 meters.

as_kilometers(["Distance"]) + as_meters(10)

Advanced build in functions for GeoAnalytics Tools buffer expressions

In addition to simple mathematical expressions, more advanced functions can be used to apply buffer expressions.


Function	Explanation	Example	Result
`constrain(<value>,<low>,<high>)`	Returns the input value if it's within the constraining bounds. If the value is less than the low value, it returns the low value. If the value is greater than the high value, it returns the high value.	constrain( ["distance"], 0, 10) constrain(['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.
`iff(<condition>,<true value>,<false value>)`	Returns one value if a condition evaluates to `true`, and another value if that condition evaluates to `false`. `<true value>` and `<false value>` can be the following: A numeric field. If there is a space in the field name, use square brackets. A number. A function.	iff(["field1"] > ["field2"], ["field1"], 0) iff(["field1"] > ["field2"], iff(["field2"] = 0, ["field3"], ["field4"]), 0)	Returns `field1` if `field1` is greater than `field2`, and `0` otherwise. Returns the result of the second `iff` 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`. `expression`—An expression. `result`—Can be a number or field. `default`—An optional value if none of the expression match.	when((["field1"] + 10) > 1, 1,(["field2"] + 10) > 2 , 2, ["field3"])	If `field1 + 10` is greater than 1, returns 1. If not, checks if `field2 + 10` is greater than 2. If yes, 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. `conditional val`—Can be a field or an expression. `case`—A value to be compared to the `conditional val`. `result`—The result if the corresponding case matches the `conditional val`. `defaultValue`—An optional value if no other values are `true`.	decode(["field1"] + 3 , ["field1"], 1, ["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.

Conditional statements can use the following operators: