Description
Resolve a supplied foot-contact displacement along a counterclockwise heading and its left normal.
Specimen measurements and animal observations depend on a defined body part, reference value, unit, and observation window. A mass fraction, size ratio, or timing share summarizes those inputs. The counting and measurement conventions must stay explicit when comparing specimens or records.
Resolve a supplied foot-contact displacement along a counterclockwise heading and its left normal.
When to use this tool
Use Animal Track Foot Contact Reference when you need to compare supplied specimen measurements or observation records under an explicit reference and denominator.
How to use the tool and how it works
- Enter contactX, contactY, referenceX, referenceY, headingDegrees. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read forward, lateral. Use the output convention below.
Subtract the reference point from the contact point, convert headingDegrees to radians, and project that displacement onto forward=(cos heading,sin heading) and lateral=(-sin heading,cos heading).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| contactX | Contact X | Required. Finite number. |
| contactY | Contact Y | Required. Finite number. |
| referenceX | Reference X | Required. Finite number. |
| referenceY | Reference Y | Required. Finite number. |
| headingDegrees | Counterclockwise heading from positive x, in degrees. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| forward | Forward | Required. Finite number. |
| lateral | Lateral | Required. Finite number. |
{
"input": {
"contactX": 4,
"contactY": 5,
"referenceX": 1,
"referenceY": 1,
"headingDegrees": 0
},
"output": {
"forward": 3,
"lateral": 4
}
}Limitations and assumptions
- This convention measures heading counterclockwise from the positive x axis. The result uses coordinate length units; it does not infer compass bearing, body orientation, or foot contact from observations.
- The field tables state structural bounds; the mechanics also specify cross-field constraints. Malformed inputs and unsupported domains cause errors. A successful false flag, empty branch value, or zero placeholder has the meaning stated above and is distinct from an input error.
- 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. Signed zero is exported as zero.
Alternative or Complementary methods
Use compatible measurements and observation records to verify the chosen denominator and reference before interpreting a specimen comparison.
References
Similar or alternative tools
- Animal Track Step Length
Return stepLength=hypot(secondX-firstX,secondY-firstY) for two supplied planar positions.
- Animal Track Stride Width Ratio
Return strideWidthRatio=strideLength/trackWidth and relativeStride=strideLength/footLength.