# CircleFit Vision Data Access functions

This topic lists the Vision Data Access functions that get values from a CircleFit structure.

Note: Each of the following functions references a CircleFit data structure for the first parameter.

Function | Description
GetDistance(CircleFit, [Index]) | Returns the distance between the indexed point and the circle. If the value is negative, the point is within the circle. If the indexed point is invalid, an #ERR is returned.
GetMaxDist(CircleFit) | Returns the distance between the circle and the point farthest from the circle. If the value is negative, the point is within the circle.
GetMaxDistIndex(CircleFit) | Returns the index of the point farthest from the circle.
GetNPointsUsed(CircleFit) | Returns the number of points used to fit the circle.
GetRadius(CircleFit, [Index]) | Returns the radius of the circle.
GetSigma(CircleFit) | Returns the square root of the sum of the squares of the distances from the points to the circle divided by the number of points.
GetX (CircleFit, [Index1], [Index2]) | Returns the X-coordinate of the center of the circle.
GetY (CircleFit, [Index], [Index]) | Returns the Y-coordinate of the center of the circle.