Description
Convert each signed rise/run fraction using atan and return second angle minus first and its absolute magnitude in radians.
Geomorphic geometry uses lengths, areas, volumes, and dimensionless shape ratios to summarize a feature. Grain axes, channel dimensions, and angular units need explicit definitions because similar field names can describe different measurements.
Convert each signed rise/run fraction using atan and return second angle minus first and its absolute magnitude in radians.
When to use this tool
Use Slope Break Angle Difference when you need a geometric summary of a supplied landform or sediment measurement.
How to use the tool and how it works
- Enter firstRisePerRun, secondRisePerRun. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedAngleRadians, absoluteAngleRadians. Use the output convention below.
Convert each signed rise/run fraction using atan and return second angle minus first and its absolute magnitude in radians.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| firstRisePerRun | First Rise Per Run | Required. Finite number. |
| secondRisePerRun | Second Rise Per Run | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| signedAngleRadians | Signed Angle Radians | Required. Finite number. |
| absoluteAngleRadians | Absolute Angle Radians | Required. Finite number. |
{
"input": {
"firstRisePerRun": 0,
"secondRisePerRun": 1
},
"output": {
"signedAngleRadians": 0.7853981633974483,
"absoluteAngleRadians": 0.7853981633974483
}
}Limitations and assumptions
- Inputs are dimensionless gradients rather than degrees or percentages; the result compares two supplied inclinations without surveying a slope break or classifying landform stability.
- 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
Inspect the measured feature and sampling method for the intended geometric definition. Use a spatial model or complete distribution when a single shape ratio or local term is insufficient.
References
Similar or alternative tools
- Alluvial Fan Radial Slope Term
Divide apexElevation-toeElevation by that distance for gradient and take atan for angleRadians.
- Dune Slipface Angle Projection
Resolve length into cosine horizontal run and sine vertical rise and return tan(angle) as slope.