Description
Convert explicit quaternion scalar-first to scalar-last ordering or the reverse under a caller source-layout flag; no normalization or rotation inference.
A quaternion has one scalar and three vector components. This family uses [w, x, y, z] unless a layout converter says otherwise. Unit quaternions can represent rotations, and q and −q describe the same rotation under this convention; component arithmetic and physical rotation interpretation are separate operations.
Convert explicit quaternion scalar-first to scalar-last ordering or the reverse under a caller source-layout flag; no normalization or rotation inference.
When to use this tool
Use this tool to convert explicit quaternion scalar-first to scalar-last ordering or the reverse under a caller source-layout flag; no normalization or rotation inference.
How to use the tool and how it works
- Enter components, scalarLast using the field definitions below.
- Run the operation. Correct input errors before interpreting an output.
- Read result.components. Use the ordering, boundary rules and absence conditions described below.
When scalarLast is true, move the last input component to the front; otherwise move the first component to the end.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| components | Four components in the input layout selected by scalarLast. | Dense list of at most 128 finite numbers; integer/shape constraints above also apply. |
| scalarLast | True means input is [x,y,z,w]; false means input is [w,x,y,z]. | A boolean true or false. |
| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.components | Four components reordered into the opposite layout selected by the flag. |
{
"input": {
"components": [
1,
2,
3,
4
],
"scalarLast": false
},
"output": {
"result": {
"components": [
2,
3,
4,
1
]
}
}
}Limitations and assumptions
- The flag describes the input layout: true converts xyzw to wxyz, false converts wxyz to xyzw.
- When an operation requires unit input, the fixed acceptance condition is |norm − 1| ≤ 1e−10. The norm audit instead uses its supplied tolerance. Angles use radians; vector units are preserved by a unit rotation. Floating-point roundoff is possible.
- Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.
Alternative or Complementary methods
Confirm component layout, multiplication order and coordinate-frame convention before using another library’s records. Normalize only when appropriate, and distinguish component-space tolerances from angular tolerances.
References
Similar or alternative tools
- Quaternion Finite Scalar Scale
Quaternion order is scalar-first [w,x,y,z], Hamilton product and right-handed active rotations; scale finite quaternion components without claiming the result remains a unit rotation.
- Axis Angle to Unit Quaternion Record
Quaternion order is scalar-first [w,x,y,z], Hamilton product and right-handed active rotations; convert an explicit nonzero axis and angle to a unit quaternion; axis is normalized, radians are not silently clamped.