Cardan Grille Hole Pattern Check
Audit actual four90° rotated caller hole pattern coverage, overlaps and uncovered cells retained, bounded even square; no security guarantee.
Description
A rotating Cardan grille should cover every cell exactly once across four orientations.
A rotating Cardan grille should cover every cell exactly once across four orientations.1
Coverage counts reveal missing or repeated cells without encrypting a message. Use Cardan Grille Hole Pattern Check to evaluate the supplied inputs under the specific model below.
When to use Cardan Grille Hole Pattern Check
Use Cardan Grille Hole Pattern Check to evaluate the supplied inputs under the specific model below. Choose the intended encoding, alphabet or check and keep the exact character, key and measurement conventions described below.
How to use Cardan Grille Hole Pattern Check and understand its results
- Choose the intended encoding, alphabet or check and keep the exact character, key and measurement conventions described below.
- Enter Grille size, Hole row column pairs using the field table and validation rules below, then run the tool.
- Read Rotation coverage counts, Uncovered cells, Overlapped cells, Valid four rotation grille and interpret units, signs, ordering and placeholders as explained below.
- If the tool reports an input error, correct that field and rerun. A successful false result, empty match list or unknown-evidence placeholder has the specific meaning described here; check the limitations before applying the result.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| grilleSize | Grille size | number | Required; constraints below |
| holeRowColumnPairs | Hole row column pairs | array of array | Required; constraints below |
Enter an even integer grille size from 2 to 64 and a nonempty array of explicit row/column hole coordinates as zero-based integers inside the square. Rotate each hole four times by (row,column)→(column,n−1−row), count every covered cell and report uncovered cells and cells hit more than once. Validity requires both counts to be zero. Overlap count counts cells rather than extra hits; no message is encrypted.
valid = uncoveredCellCount==0 and multiplyCoveredCellCount==0 across four rotations Field order, units and branch conditions follow the implementation explanation above.
| Output field | Meaning | Value type |
|---|---|---|
| rotationCoverageCounts | Rotation coverage counts | array of array |
| uncoveredCells | Uncovered cells | number |
| overlappedCells | Overlapped cells | number |
| validFourRotationGrille | Valid four rotation grille | boolean |
{
"input": {
"grilleSize": 2,
"holeRowColumnPairs": [
[
0,
0
]
]
},
"output": {
"rotationCoverageCounts": [
[
1,
1
],
[
1,
1
]
],
"uncoveredCells": 0,
"overlappedCells": 0,
"validFourRotationGrille": true
}
}Limitations and assumptions
Coverage counts reveal missing or repeated cells without encrypting a message. Apply the exact scope and assumptions described above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are stated above; extremely large inputs or outputs can also be rejected. These errors differ from successful results such as false, no matches or unknown evidence.
Alternative or Complementary methods
Use Enigma Plugboard Pairing Count Check for a related task: An Enigma plugboard pairs letters without sharing a letter between pairs.
Use Route Spiral Transposition Tool for a related task: A spiral route reads cells around a filled rectangle in a chosen direction.
References
-
Cardan Grille Hole Pattern Check — tool.io
Similar or alternative tools
- Enigma Plugboard Pairing Count Check
An Enigma plugboard pairs letters without sharing a letter between pairs.
- Route Spiral Transposition Tool
A spiral route reads cells around a filled rectangle in a chosen direction.