# Calibrate Vision Data Access functions

This topic lists the Vision Data Access functions that get values from Calibrate Functions.

Function | Description
GetMaxError | Returns the maximum expected error (in pixels) when mapping coordinates using the transform.
GetMeanError | Returns the mean expected error (in pixels) when mapping coordinates using the transform
GetNFound(Structure) | Returns the number of points found for a CalibPoints data structure.
GetWorldUnits | Returns a string containing the short-hand notation of the world-units associated with the coordinate transform.
Unit of Measurement | Result String
Microns | "µm"
Millimeters | "mm"
Centimeters | "cm"
Inches | "in"