Description
Convert a supplied research stimulus coordinate step under an explicit angular calibration, without an acuity interpretation.
Optical calculations distinguish lens power in diopters, prism notation, angular axes, geometric distances, and visual-acuity reporting scales. Sign conventions and length units are especially important when a formula combines power with decentration or vertex distance. A supplied model term is separate from a validated visual test or prescription.
Convert a supplied research stimulus coordinate step under an explicit angular calibration, without an acuity interpretation.
When to use this tool
Use Visual Stimulus Angular Step when you need this explicit optical, chart, frame, axis, or reference conversion with compatible supplied units.
How to use the tool and how it works
- Enter firstPosition, secondPosition, suppliedRadiansPerUnit. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read stepRadians, stepDegrees. Use the output convention below.
For positive suppliedRadiansPerUnit return stepRadians=(secondPosition-firstPosition)*factor and stepDegrees=stepRadians*180/pi.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| firstPosition | First Position | Required. Finite number. |
| secondPosition | Second Position | Required. Finite number. |
| suppliedRadiansPerUnit | Positive radians per supplied position unit. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| stepRadians | Step Radians | Required. Finite number. |
| stepDegrees | Step Degrees | Required. Finite number. |
{
"input": {
"firstPosition": 0,
"secondPosition": 2,
"suppliedRadiansPerUnit": 0.017453292519943295
},
"output": {
"stepRadians": 0.03490658503988659,
"stepDegrees": 2
}
}Limitations and assumptions
- Positions share one source coordinate unit and the supplied multiplier assumes a linear angular mapping. It is not a geometric visual-angle calculation from distance and stimulus size or a clinical test calibration.
- 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
Use the appropriate complete optical or measurement model when a scalar term is insufficient. Verify power, axis, length, notation, and reference conventions before applying the result within a broader assessment.
References
Similar or alternative tools
- Visual Stimulus Distance Factor
For nonnegative recordedDistance and positive sourceToTargetFactor return distance=recordedDistance*factor.
- Chart Acuity Step Budget
Count supplied chart index steps inclusively; no visual acuity conversion or scoring is assumed.