# CircleFit Vision Data Access functions

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

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

Function Functions are tools that are available in Spreadsheet for processing and analyzing acquisitions or other results. You can add functions to your Spreadsheet job to create tool chains and produce results for specific applications. | Description
GetDistance(CircleFit, [Index]) | Returns the distance between the indexed point and the circle in pixels. 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 in pixels. 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 in pixels.
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.