This is a direct reproduction of the post on Vector as written by Bryce Larson as it appears in the Punkworks sub-forum on TechPB.

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OK, since it’s a common term used constantly by CockerPunk and me – I thought I would whip up a quick tutorial on what the term vector is and what we think it means.

I’ll use the following data – it’s from a previous test:

And here’s a graph of that data – the blue square is the mean impact location – or the center of this group.

Here’s the data corrected to 0,0. You don’t need to do this to calculate the vector – but it will make this tutorial make more sense.

Here’s the data again – the Standard Deviations of X and Y have been graphed – as the green triangle.

Here’s the hypotenuse of the SD – OR, a line from 0,0 to the point where the X and Y standard deviations land

Here’s the vector displayed as a radius of a circle. In theory that circle should encompass 68% of the shots. In this case it contains 15 of the 22 shots – which, happily, is 68% of them.

Here’s a graph with a circle with a radius of 2x the vector. Theoretically, this circle should encompass 95% of all shots ever fired by this setup. We have none outside – but that’s because we don’t have a large enough sample.

hope this helps.