Hearts and Arrows Precision Check
Audit caller aligned eight-arrow angular/radial measurements against declared pattern precision; no automated hearts detection, branded cut certification or correction for lighting/registration.
Description
An aligned eight-arrow pattern can be compared with ideal 45-degree spacing.
An aligned eight-arrow pattern can be compared with ideal 45-degree spacing. Angular error and radial uniformity are separate supplied precision criteria.1
Audit caller aligned eight-arrow angular/radial measurements against declared pattern precision; no automated hearts detection, branded cut certification or correction for lighting/registration.
When to use Hearts and Arrows Precision Check
Use this tool to audit caller aligned eight-arrow angular/radial measurements against declared pattern precision; no automated hearts detection, branded cut certification or correction for lighting/registration.
Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
How to use Hearts and Arrows Precision Check and understand its results
- Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
- Enter observedEightArrowAxisDegrees, observedEightArrowRadii, callerIdealPhaseDegrees, callerAngularToleranceDegrees, callerRelativeRadialTolerance using the field table and calculation rules, then run the tool.
- Read wrappedArrowAngularErrorsDegrees, relativeArrowRadialRange, withinCallerPatternPrecision. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| observedEightArrowAxisDegrees | Observed eight arrow axis degrees | list of number | Required |
| observedEightArrowRadii | Observed eight arrow radii | list of number | Required |
| callerIdealPhaseDegrees | Caller ideal phase degrees | number | Required |
| callerAngularToleranceDegrees | Caller angular tolerance degrees | number | Required |
| callerRelativeRadialTolerance | Caller relative radial tolerance | number | Required |
Enter exactly eight aligned axes and positive radii, an ideal phase and nonnegative angular/radial tolerances. Wrap angular errors to [−180°,180°), compute relative radial range and require both maximum absolute angular error and radial range≤their limits.
angular error=wrapped(observed angle−phase−45°index); radial range=(max radius−min radius)/mean radius Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| wrappedArrowAngularErrorsDegrees | Wrapped arrow angular errors degrees | list of number |
| relativeArrowRadialRange | Relative arrow radial range | number |
| withinCallerPatternPrecision | Within caller pattern precision | boolean |
{
"input": {
"observedEightArrowAxisDegrees": [
0,
45,
90,
135,
180,
225,
270,
315
],
"observedEightArrowRadii": [
1,
1,
1,
1,
1,
1,
1,
1
],
"callerIdealPhaseDegrees": 0,
"callerAngularToleranceDegrees": 1,
"callerRelativeRadialTolerance": 0.1
},
"output": {
"wrappedArrowAngularErrorsDegrees": [
0,
0,
0,
0,
0,
0,
0,
0
],
"relativeArrowRadialRange": 0,
"withinCallerPatternPrecision": true
}
}Limitations and assumptions
There is no automatic hearts detection, image registration or branded cut certification.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use Optical Symmetry Score: Audit aligned image brightness asymmetry about declared horizontal/vertical mirror axes, normalized to total flux; unlike paired physical outline error, illumination/registration remain confounders and no automatic alignment. For a complementary task, use Cut Grade Point Aggregator: Aggregate caller calibrated cut component assessments while separately retaining mandatory-component vetoes; high weighted score does not override failed local criteria or create a laboratory cut grade.
References
-
Hearts and Arrows Precision Check — tool.io
Similar or alternative tools
- Optical Symmetry Score
Audit aligned image brightness asymmetry about declared horizontal/vertical mirror axes, normalized to total flux; unlike paired physical outline error, illumination/registration remain confounders and no automatic alignment.
- Cut Grade Point Aggregator
Aggregate caller calibrated cut component assessments while separately retaining mandatory-component vetoes; high weighted score does not override failed local criteria or create a laboratory cut grade.