Feature Description
The common operators provided by SuperMap include three types: basic arithmetic operators, relational operators, and logical operators.
Commonly used operators are described as follows:
Arithmetic Operations
Common arithmetic operations include addition (+), subtraction (-), multiplication (*), and division (/). The table below details how each calculation method is used when performing raster algebraic operations.
| Type of Operation | Description | Illustration |
| Addition | Addition in raster algebraic operation is the process of adding the cell values of two input raster datasets cell by cell. |  |
| Subtraction | Subtraction in raster algebraic operation is used to subtract one raster dataset from another, i.e., subtracting the cell value of the corresponding location in the second dataset from the cell value in the first raster dataset cell by cell.
The order of input raster datasets is important when using subtraction. If the order is different, the results are usually also different. |
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| Multiplication | Multiplication in raster algebraic operation is the process of multiplying the raster values of two input raster datasets cell by cell. |  |
| Division | Division in raster algebraic operation is the process of dividing the raster values of two input raster datasets cell by cell. |  |
Relational Operations
Common relational operations include greater than (>), less than (<), equal to (=), not equal to (≠), greater than or equal to (≥), and less than or equal to (≤). The table below details how each calculation method is used when performing raster algebraic operations.
| Type of Operation | Description |
| Greater Than | The Greater Than operation in raster algebra outputs the cell values from input dataset 1 that are greater than those in input dataset 2. |
| Less Than | The Less Than operation in raster algebra outputs the cell values from input dataset 1 that are less than those in input dataset 2. |
| Equal To | The Equal To operation in raster algebra outputs the cell values from input dataset 1 that are equal to those in input dataset 2. |
| Not Equal To | The Not Equal To operation in raster algebra outputs the cells where the raster values of the two input raster datasets are not equal, cell by cell. |
| Greater Than or Equal To | The Greater Than or Equal To operation in raster algebra outputs the cell values from input dataset 1 that are greater than or equal to those in input dataset 2. |
| Less Than or Equal To | The Less Than or Equal To operation in raster algebra outputs the cell values from input dataset 1 that are less than or equal to those in input dataset 2. |
Logical Operations
Logical operations, also known as Boolean operations, perform conditional judgments of "true" or "false" on the cell values of input raster datasets and output them in binary form (1 and 0). The operation result is represented by 1 or 0, where 1 logically represents "true", meaning raster cells that meet the requirements of the algebraic operation expression; 0 logically represents "false", meaning raster cells that do not meet the requirements of the algebraic operation expression.
Common logical operations include And, Or, Not, and Xor. The details of each logical calculation method are described below.
| Type of Operation | Description |
| And | Represents the logical "AND", denoted by & in the expression dialog. A cell is true and assigned a value of 1 if and only if its value in the raster dataset satisfies both algebraic operation expressions simultaneously; otherwise, it is false and assigned a value of 0. |
| Or | Represents the logical "OR", denoted by | in the expression dialog. A cell is true and assigned a value of 1 if its value in the raster dataset satisfies at least one of the two algebraic operation expressions; if the cell value satisfies neither expression, it is false and assigned a value of 0. |
| Not | Represents the logical "NOT", denoted by Not( ) in the expression dialog. A cell is true and assigned a value of 1 if its value in the raster dataset does not satisfy the listed algebraic operation expression; otherwise, it is false and assigned a value of 0. |
| Xor | Represents the logical "Exclusive OR" (XOR), denoted by ^ in the expression dialog. A cell is true and assigned a value of 1 if and only if its value in the raster dataset satisfies exactly one of the two algebraic operation expressions; if the cell value satisfies both expressions or satisfies neither, it is false and assigned a value of 0. |