Description
Return a permutation's inverse position.
Bit positions are usually counted from the least-significant bit, while a displayed binary string has its own left-to-right indexing convention. Masks, fields and parity predicates describe a selected region or pattern; local agreement does not validate a complete encoded record.
Return a permutation's inverse position.
When to use this tool
Use Bit Permutation Inverse Position when checking the stated mask, field, parity or bit-index convention.
How to use the tool and how it works
- Enter permutation, position. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read inverse. Use the output convention below.
Return a permutation's inverse position. Require a nonempty unique in-range integer permutation and valid position; inverse = permutation.indexOf(position).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| permutation | Permutation | Required. Array of safe integer; maximum items 256. |
| position | Position | Required. Safe integer; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| inverse | Inverse | Required. Safe integer. |
{
"input": {
"permutation": [
2,
0,
1
],
"position": 0
},
"output": {
"inverse": 1
}
}Limitations and assumptions
- This finds one inverse mapping entry, not the complete inverse permutation or a bit-reordered word.
- 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
Choose an explicit bit order, word width and missing-position policy; use the complete record format and appropriate parsing or checksum methods for full validation.
References
Similar or alternative tools
- Bitword Deposit One Bit Position
Write one Boolean bit into a bounded word.
- Bitwise: Bit Word Hex Digit Boundary Padding
Format a bounded word as fixed-width uppercase hexadecimal.