# PairDistance

Computes the distance between two edges of an Edge data structure. PairDistance references two edges, by index number, and reports the distance between their midpoints. The segment over which the edge-to-edge distance is computed is derived from the region originally used to extract the edges from the image.

Note: If the PairDistance function is added to an Abs Math formula, [for example, Abs(B2)+PairDistance(C2,0,1)] it is recommended to insert the PairDistance function in its own spreadsheet cell and use Cell References into the Abs formula.

## PairDistance Inputs

Parameter | Description
Edges | A reference to a spreadsheet cell containing an Edge data structure, which must consist of multiple straight-line edges.
First Edge | Specifies the index number (0 to 10000; default = 0) of the first edge of an edge pair.
Second Edge | Specifies the index number (0 to 10000; default = 1) of the second edge of an edge pair.

## PairDistance Outputs

Returns | A value representing the arc distance between edges, or #ERR if any of the input parameters are invalid.