An overview of the Map Algebra Operators (arcpy.sa)

Spatial Analyst Map Algebra supports a series of operators. The operators can be grouped into Arithmetic, Bitwise, Boolean, and Relational categories. The available operators and their categories are listed below.

The operators are overloaded since they exist in both Spatial Analyst and Python. To distinguish whether an input is a raster as opposed to a scalar variable, the input raster is cast using the Raster class: Raster("inRas").

In operators that accept two inputs, if both inputs are scalars, the Python operator will be used working on scalars. If one or both of the inputs are rasters (identified by casting with the Raster class), the Spatial Analyst operator is used and will work on each cell within the rasters. For those operators that accept a single input, if it is a scalar, then the Python operator is used; if a raster is input, the Spatial Analyst operator is used.

Map Algebra operator

Description

Spatial Analyst GP tool

ArcGIS 9.x Map Algebra equivalent

Arithmetic

+ (link)

Addition

Plus

+

+ (link)

Unary Plus

N/A

N/A

- (link)

Subtraction

Minus

-

- (link)

Unary Minus

Negate

-

* (link)

Multiplication

Times

*

** (link)

Power

Power

N/A

/ (link)

Division

Divide

/, div

// (link)

Integer Division

N/A

N/A

% (link)

Modulo

Mod

Mod

Bitwise

<< (link)

Bitwise Left Shift

Bitwise Left Shift

<<

>> (link)

Bitwise Right Shift

Bitwise Right Shift

>>

Boolean

& (link)

Boolean And

Boolean And

&, and

~ (link)

Boolean Complement

Boolean Not

^, not

| (link)

Boolean Or

Boolean Or

|, or

^ (link)

Boolean Exclusive Or

Boolean XOr

!, xor

Relational

== (link)

Equal To

Equal To

==, eq

> (link)

Greater Than

Greater Than

>, gt

>= (link)

Greater Than or Equal To

Greater Than Equal

>=, ge

< (link)

Less Than

Less Than

<, lt

<= (link)

Less Than or Equal To

Less Than Equal

<=, le

!= (link)

Not Equal To

Not Equal

^=, <>, ne

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9/12/2013