NXV — Node-Crossing Vectors

Node Crossing Vectors · NXV

Node Crossing Vectors by Dr Keith Strang Reid Cailleach Computing Ltd 2026.

NXV is an exact combinatorial extension of Mann-Whitney U for tied data and small clinical rating scales.

Enter two samples and get a p-value. NXV allows for ties in a way that Mann-Whitney U does not. Perhaps you are using a rating scale. If you are just counting, don't worry about r.

But if you are using a scale that only has 7 possible scores, then put r as 7. How many tied elements do you expect? That is λ. If you don't expect any ties then λ is 0. r and λ interact but the app will keep you right.

This is BETA version 0.3 - "introducing a grey area" 2150 GMT Sep 6 2026

Version "introducing a grey area" introduces a greyscale button for legibility.

Version "introducing a grey area" has no known bugs and does nto change the sha256 checksum for distributions.

Parameters

S smaller sample · up to 10 values · space-separated · decimal point e.g. 3.14

T other sample · up to 10 values · space-separated · decimal point e.g. 3.14

r scale range size (integer, e.g. CGI r=7)

λ expected tied elements per sample (0 ≤ λ ≤ n−1)

Results

NXV null distribution will appear here