Description
Validate permutation as unique integer indices covering its own length and select a valid index.
Matrix shapes can be empty or have singleton axes without containing a scalar. Broadcasting expands singleton dimensions under an explicit axis-by-axis compatibility rule.
Validate permutation as unique integer indices covering its own length and select a valid index.
When to use this tool
Use Matrix Permutation Fixed Point Entry when you need a matrix shape, count, or structural entry classification.
How to use the tool and how it works
- Enter permutation, index. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read diagonal, fixed. Inspect fixed before interpreting the associated values.
Validate permutation as unique integer indices covering its own length and select a valid index. Return diagonal one when permutation[index] equals index, otherwise zero.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| permutation | Permutation | Required. Array of safe integer; maximum items 256. |
| index | Index | Required. Safe integer; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| diagonal | Diagonal | Required. Safe integer. |
| fixed | Fixed | Required. Boolean. |
{
"input": {
"permutation": [
1,
0,
2
],
"index": 2
},
"output": {
"diagonal": 1,
"fixed": true
}
}Limitations and assumptions
- This inspects one fixed point rather than constructing the full permutation matrix.
- 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
Check all axes and actual data lengths when validating a complete matrix or broadcast operation.
References
Similar or alternative tools
- Matrix Kronecker Delta Entry
Return one when nonnegative row equals column and zero otherwise.
- Matrix: Matrix Shape Degenerate Axis Tag
Allow zero dimensions.