esri_coordsys_DatumTransformations (AutoLISP)

This function returns all the datum transformation definitions in the drawing as a list of associated lists.

The combination of the from coordinate system and to coordinate system included in each datum transformation definition is unique and acts as key values that distinguish one datum transformation definition from another in the drawing. Each datum transformation definition includes a list of steps used to perform the transformation. Each step has a direction that indicates the order the coordinate system transformation step is applied.

Syntax

(esri_coordsys_DatumTransformations)

• None

Example usage 1

Request the list of datum transformations in a drawing that contains five datum transformations:

``(esri_coordsys_DatumTransformations)``

Result example usage 1

Returns a list that includes the five datum transformations found in the example drawing.

``((("From" . "2882") ("To" . "3857") ("Transformation" ((("Direction" . "Forward") ("Step" . "1901"))))) (("From" . "6425") ("To" . "3857") ("Transformation" ((("Direction" . "Reverse") ("Step" . "108355")) (("Direction" . "Reverse") ("Step" . "108282"))))) (("From" . "6443") ("To" . "3857") ("Transformation" ((("Direction" . "Reverse") ("Step" . "108363"))))) (("From" . "3857") ("To" . "4432") ("Transformation" ((("Direction" . "Reverse") ("Step" . "1173")) (("Direction" . "Forward") ("Step" . "1241"))))) (("From" . "102118") ("To" . "3857") ("Transformation" ((("Direction" . "Forward") ("Step" . "1173"))))) (("From" . "6543") ("To" . "3857") ("Transformation" ((("Direction" . "Reverse") ("Step" . "108354"))))))``

Example usage 2

Request the list of datum transformations in a drawing that has no datum transformations set:

``(esri_coordsys_DatumTransformations)``

Result example usage 2

Returns the message that no datum transformations were set in the drawing.

``(nil ("Error" . "No datum transformations found."))``

Return values

• All the datum transformations in the drawing are returned as a list of associated lists.
• If the function fails, a list with the first value of nil is returned followed by an associated list containing the key value "Error" and an associated error message as a string: (nil ("Error" . "<message>")).

Failed return values

A failed return value can occur for the following reason:

• (nil ("Error" . "No datum transformations found."))

No datum transformations have been set in the drawing.