Computes a new categorical raster map by evaluating an algebraic or logical expression independently for every cell in the output map. Functionally identical to Calculate Map — the same inputs, parameters, and expression language apply — but the output is typed as a categorical map, which preserves category semantics for downstream functors that distinguish categorical maps from continuous maps (e.g. Calc Areas, For Each Category).
Use this functor when the expression produces integer class codes rather than measured or continuous values. If the expression produces continuous or measured values, use Calculate Map instead.
The abbreviated syntax (also called shorthand) for this functor is ##. See Calculator functor shorthand in the EGO Script documentation for the full syntax of both the verbose and abbreviated forms, and Calculate Functors — Complete Operator Documentation for the complete expression language reference.
| Name | Type | Description |
|---|---|---|
| Expression | Image Expression Type | The algebraic or logical formula used to compute each output cell's category code. Must be enclosed in square brackets [ ] in EGO Script. |
| Name | Type | Default | Description |
|---|---|---|---|
| Cell Type | Cell Type Type | Signed 32-bit Integer | Data type for each output cell. |
| Null Value | Null Value Type | Based on Cell Type | Sentinel value representing “no data” in the output. |
| Result Is Sparse | Boolean Value Type | False | If true, only non-null cells are stored in memory — saves memory but slows random access. |
| Result Format | Map Type | None | Optional reference map whose spatial format (extent, resolution, projection) is applied to the output. Category information in the reference map is ignored. Prefer this port over a Number Map hook when the map is needed only for format purposes — a hook defines an identifier in the expression namespace and blocks abbreviated syntax if that identifier is unused in the expression. |
| Name | Type | Description |
|---|---|---|
| Result | Categorical Map Type | The computed categorical output map. |
All behaviour — hook functor wiring, spatial context, image virtualization, available expression features, null value handling, and performance — is identical to Calculate Map. See the Notes section of that page for full details.
CalculateCategoricalMap