Cortex Percentage Flake Estimator

Summarize measured dorsal cortex coverage per flake and pooled physical area, distinguishing unequal-sized flakes from a mean percentage.

Description

Dorsal cortex percentages describe measured coverage on flakes.

Dorsal cortex percentages describe measured coverage on flakes. Pooling actual areas weights large flakes more heavily than an arithmetic mean of their individual percentages.^[1]

Summarize measured dorsal cortex coverage per flake and pooled physical area, distinguishing unequal-sized flakes from a mean percentage.

When to use Cortex Percentage Flake Estimator

Use this tool to summarize measured dorsal cortex coverage per flake and pooled physical area, distinguishing unequal-sized flakes from a mean percentage.

Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.

How to use Cortex Percentage Flake Estimator and understand its results

Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
Enter observedCortexAreasMm2, observedDorsalAreasMm2 using the field table and calculation rules, then run the tool.
Read perFlakeCortexPercentages, pooledAreaCortexPercentage. 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
observedCortexAreasMm2	Observed cortex areas mm2	list of number	Required
observedDorsalAreasMm2	Observed dorsal areas mm2	list of number	Required

Pair nonnegative observed cortex areas with positive dorsal areas in mm². Cortex cannot exceed dorsal area on any flake. Return each percentage and the area-weighted pooled percentage.

Paired lists must be nonempty and have equal lengths.

perFlakePercent = 100 cortexArea/dorsalArea; pooledPercent = 100ΣcortexArea/ΣdorsalArea

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
perFlakeCortexPercentages	Per flake cortex percentages	list of number
pooledAreaCortexPercentage	Pooled area cortex percentage	number

json

{
  "input": {
    "observedCortexAreasMm2": [
      1,
      0,
      6
    ],
    "observedDorsalAreasMm2": [
      2,
      2,
      6
    ]
  },
  "output": {
    "perFlakeCortexPercentages": [
      50,
      0,
      100
    ],
    "pooledAreaCortexPercentage": 70
  }
}

Limitations and assumptions

Coverage must be measured on a consistent dorsal-surface basis. The tool does not assign a reduction stage or correct for unobservable surfaces and recovery bias.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. 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.

Alternative or Complementary methods

Use Flake Reduction Stage Classifier: Apply explicit caller cortex-band reduction-stage codes without a universal lithic technology rule; cortex alone does not establish the true manufacturing stage. For a complementary task, use Edge Retouch Index: Compute observed linear edge retouch coverage and extreme bounds for missing edge; not scar-depth intensity or a manufacturing/usage diagnosis.

References

Cortex Percentage Flake Estimator — tool.io

Similar or alternative tools

Flake Reduction Stage Classifier
Apply explicit caller cortex-band reduction-stage codes without a universal lithic technology rule; cortex alone does not establish the true manufacturing stage.
Edge Retouch Index
Compute observed linear edge retouch coverage and extreme bounds for missing edge; not scar-depth intensity or a manufacturing/usage diagnosis.