Description
Test exact zero cross-product for parallel, positive dot product for sameDirection, and accept parallel vectors under the supplied opposite-direction policy.
Research image measurements depend on scale, orientation, landmarks, and reference planes. A coordinate or area-support calculation uses supplied inputs without examining an image or identifying anatomy.
Test exact zero cross-product for parallel, positive dot product for sameDirection, and accept parallel vectors under the supplied opposite-direction policy.
When to use this tool
Use Pelvic Image Reference Plane Flag when you need one transparent image-scale or orientation component.
How to use the tool and how it works
- Enter normal, reference, allowOpposite. Keep parallel arrays aligned. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read parallel, sameDirection, accepted. Inspect parallel, sameDirection, accepted before interpreting the associated values.
Require nonzero three-component normal and reference vectors. Test exact zero cross-product for parallel, positive dot product for sameDirection, and accept parallel vectors under the supplied opposite-direction policy.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| normal | Normal | Required. Array of finite number; maximum items 256. |
| reference | Supplied reference token under the supported grammar. | Required. Array of finite number; maximum items 256. |
| allowOpposite | Allow Opposite | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| parallel | Parallel | Required. Boolean. |
| sameDirection | Whether the normals have a positive dot product; this alone does not establish parallelism. | Required. Boolean. |
| accepted | Accepted | Required. Boolean. |
{
"input": {
"normal": [
0,
0,
1
],
"reference": [
0,
0,
-1
],
"allowOpposite": true
},
"output": {
"parallel": true,
"sameDirection": false,
"accepted": true
}
}Limitations and assumptions
- No numerical tolerance is used; sameDirection can be true without parallel, and floating-point limits can affect the check. Plane location, image registration, anatomical orientation, and diagnosis are not evaluated.
- 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
Verify image calibration, anatomical reference conventions, measurement uncertainty, and professional interpretation separately.
References
Similar or alternative tools
- Specimen Side Clockface Source Pair
Map clock position to degrees clockwise from twelve, reverse the angle when mirrored, compare views literally, and serialize side, view, and clock position as sourceKey.
- Pelvic Image Support Share
Sum visible area and the visible subset with both support flags, returning their ratio or zero with defined false.