# Match by date

### Description
Both inputs `A [OBJ,DATE]` and `B [OBJ,DATE]` contain pairs `[candidate, evidence]`.
The block compares the evidence columns from the inputs and return as matches the corresponding candidate objects.

Optional input `Cands [OBJ,OBJ]` can limit the matching to only the pairs of candidates listed.
- The first column corresponds to the candidate column of `A`.
- The second column corresponds to the candidate column of `B`.
- Scores are propagated to final matches.

### Input
- `A [OBJ,DATE]`: a list of `[candidate, evidence]` pairs, in which the `evidence` column will be used for comparison and the `candidate` column will be the result
- `Cands [OBJ,OBJ]` (optional) : candidate pairs, only candidate columns of `A` and `B` that are in `Cands` will be matched
- `B [OBJ,DATE]`: a list of `[candidate, evidence]` pairs, in which the `evidence` column will be used for comparison and the `candidate` column will be the result

### Output
- `RESULT [OBJ,OBJ]`: the matched `candidate` items from `A` and `B`
- `NOTA [OBJ]`: the `candidate` items from `A` that did not match with an item from `B`
- `NOTB [OBJ]`: the `candidate` items from `B` that did not match with an item from `A`

### Parameters
- `Comparison`: Comparison function to use (`=`,`!=`,`<`,`>`,`<=`,`>=`,`day-distance`)
- `Max day-distance`: when `Comparison` is set to `day-distance`, the match is valid only if the difference in days between the two dates is not greater than this value
- `Slope`: positive value determining the slope of the ranking curve.
  The higher the slope, the closer together the resulting scores.
- `Exclude self-matches`: whether to emit the match if the objects in `A` and `B` are the same. Mostly useful when `A` and `B` come from the same source
- `Exclude symmetrical matches`: whether to keep only one between matches `A-B` and `B-A`. It cannot be predicted which of the two is kept.