Companion checker

Two to twelve crops. The matrix shows a stored pair or no data. An unknown pair is never shown as bad.

Crop figures are cited from public agriculture pages, including the Department of Agriculture Sri Lanka.

Methodology

Where do the pair labels come from?: Only from companion rows stored with a source. Good, bad, and neutral are passed through with that source. A missing pair is labelled no data.
Why is the matrix empty?: No citable companion source was added. Blog charts were not copied in. Until a row exists, every cell stays no data, which is not a bad pairing.
When is a swap suggested?: Only when a third crop is stored as good with both sides of a bad pair, and that crop is not already in the bed. With an empty table, no swap is suggested.