Description
For order in 1-128, enumerate the last column above the diagonal and then the whole last row, returning aligned zero-based row and column arrays.
A matrix coordinate, a storage offset, and a block-local coordinate are different representations. Shape, stride, origin, and transpose conventions determine the correct mapping.
For order in 1-128, enumerate the last column above the diagonal and then the whole last row, returning aligned zero-based row and column arrays.
When to use this tool
Use Matrix Leading Principal Border Index when you need one explicit matrix-coordinate or address conversion.
How to use the tool and how it works
- Enter order. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read rowIndices, columnIndices. Use the output convention below.
For order in 1-128, enumerate the last column above the diagonal and then the whole last row, returning aligned zero-based row and column arrays.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| order | Order | Required. Safe integer; minimum 1; maximum 128. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| rowIndices | Row Indices | Required. Array of safe integer; maximum items 256. |
| columnIndices | Column Indices | Required. Array of safe integer; maximum items 256. |
{
"input": {
"order": 3
},
"output": {
"rowIndices": [
0,
1,
2,
2,
2
],
"columnIndices": [
2,
2,
0,
1,
2
]
}
}Limitations and assumptions
- The shared corner appears once; this lists a leading principal border without retrieving matrix values.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Validate the full shape, memory span, and storage convention before using the resulting index.
References
Similar or alternative tools
- Matrix Antidiagonal Entry Index
Use the selected zero- or one-based position as row and subtract its zero-based offset from the final column.
- Matrix: Matrix Diagonal Offset Length
For signed offset, skip max(0, -offset) rows and max(0, offset) columns.