# Calculate Lookup Table

## Description

This container calculates a lookup table using algebraic/logical expression involving tables and values.

## Inputs

Name | Type | Description |
---|---|---|

Expression | Image Expression | Algebraic or logical expression used to calculate the lookup table. |

## Output

Name | Type | Description |
---|---|---|

Result | Lookup Table | Output lookup table. |

## Group

## Notes

The table defined using the identifier 1, i.e. the table corresponding to “t1” in the calculation, is used to define the format of the resulting table.

If the calculation of the expression diverges, the corresponding table key is not inserted in the output table. So, when possible way to remove a key from a table is returning *null*.

The list of mathematical and logical operators that can be employed in the logic/algebraic expression can be found in the image expression reference. Note that the operators and functions described in Image Operators and Functions and Image Neighborhood Functions can not be used in lookup table calculations.

The tables used by the “Calculate Lookup Table” must be provided by a corresponding Number Table and the values must be provided by a corresponding Number Value.

## Internal Name

CalculateLookupTable