Description
apparentFrequency = intersections/scanLength; normalFrequency divides by abs(cos(angle)); normalSpacing is its reciprocal.
Geological orientations and component projections require explicit axis, angle and sign conventions. A straight segment or planar-set correction is a geometric model, not an independently measured structure or hazard assessment.
apparentFrequency = intersections/scanLength; normalFrequency divides by abs(cos(angle)); normalSpacing is its reciprocal.
When to use this tool
Use Rock Fracture Spacing Frequency Factor when checking one supplied geological orientation or displacement projection.
How to use the tool and how it works
- Enter intersections, scanLength, angleFromNormal. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read apparentFrequency, normalFrequency, normalSpacing. Use the output convention below.
Require positive whole intersections and positive scanLength and angleFromNormal strictly between -pi/2 and pi/2. apparentFrequency = intersections/scanLength; normalFrequency divides by abs(cos(angle)); normalSpacing is its reciprocal.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| intersections | Intersections | Required. Safe integer; minimum 1. |
| scanLength | Scan Length | Required. Finite number; strictly above 0. |
| angleFromNormal | Angle From Normal | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| apparentFrequency | Apparent Frequency | Required. Finite number. |
| normalFrequency | Normal Frequency | Required. Finite number. |
| normalSpacing | Normal Spacing | Required. Finite number. |
{
"input": {
"intersections": 10,
"scanLength": 20,
"angleFromNormal": 0
},
"output": {
"apparentFrequency": 0.5,
"normalFrequency": 0.5,
"normalSpacing": 2
}
}Limitations and assumptions
- The angle is radians from the fracture-set normal. This assumes one planar set and comparable intersections; orientation bias, sampling uncertainty and practical stability are not assessed.
- 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 verified observations, reference directions and full geometry before interpreting real structures or practical stability.
References
Similar or alternative tools
- Fault Displacement Component Projection Term
strikeSlip = slip*cos(rake); dipSlip = slip*sin(rake); horizontalAcrossStrike = dipSlip*cos(dip); verticalDown = dipSlip*sin(dip).
- Borehole Depth Inclination Vertical Term
verticalIncrement = length*cos(inclination); horizontalIncrement = length*sin(inclination); finalDepth = initialDepth+verticalIncrement.