TSI Composite Average Calculator

Compute caller-requested diagnostic arithmetic of actual three Carlson indices with explicit weights, missing-evidence coverage and disagreement. NALMS cautions that averaging these indices is inappropriate for estimating algal biomass; prefer chlorophyll and examine index deviations. This is not a recommended ecological classifier or lake-state certification.

Description

Secchi, phosphorus and chlorophyll indices can disagree for meaningful reasons.

Secchi, phosphorus and chlorophyll indices can disagree for meaningful reasons. NALMS advises against averaging them to estimate algal biomass; this tool only reports caller-requested diagnostic arithmetic.^{[1, 2]}

Enter exactly three finite indices in Secchi/P/chlorophyll order, binary evidence and nonnegative weights with positive total and some positive-weight evidence. Normalize weights, omit unknowns and return composite, completeness, known-weight fraction and max−min observed disagreement.

When to use TSI Composite Average Calculator

Use TSI Composite Average Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. This is not a recommended ecological classifier. Disagreement includes observed zero-weight entries; prefer examining the separate indices.

Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.

How to use TSI Composite Average Calculator and understand its results

Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
Enter secchiPhosphorusChlorophyllTsi, indexEvidenceFlags, callerIndexWeights using the field table and calculation rules, then run the tool.
Read availableEvidenceCompositeTsi, allThreeIndexEvidenceAvailable, knownIndexWeightFraction, maxObservedIndexDisagreement. 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
secchiPhosphorusChlorophyllTsi	Secchi phosphorus chlorophyll tsi	list of number	Required
indexEvidenceFlags	Index evidence flags	list of number	Required
callerIndexWeights	Caller index weights	list of number	Required

composite=sum(normalizedWeight×knownFlag×TSI)/knownWeight

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

Output field	Meaning	Value type
availableEvidenceCompositeTsi	Available evidence composite tsi	number
allThreeIndexEvidenceAvailable	All three index evidence available	boolean
knownIndexWeightFraction	Known index weight fraction	number
maxObservedIndexDisagreement	Max observed index disagreement	number

json

{
  "input": {
    "secchiPhosphorusChlorophyllTsi": [
      40,
      50,
      60
    ],
    "indexEvidenceFlags": [
      1,
      1,
      0
    ],
    "callerIndexWeights": [
      1,
      1,
      1
    ]
  },
  "output": {
    "availableEvidenceCompositeTsi": 45,
    "allThreeIndexEvidenceAvailable": false,
    "knownIndexWeightFraction": 0.6666666666666666,
    "maxObservedIndexDisagreement": 10
  }
}

Limitations and assumptions

This is not a recommended ecological classifier. Disagreement includes observed zero-weight entries; prefer examining the separate indices.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use TSI Carlson Chlorophyll Calculator: Chlorophyll is an algal-pigment proxy. Carlson’s empirical index relates its concentration to a continuous trophic-state scale. For a complementary task, use Trophic Category Classifier: Trophic categories divide a continuous index using an explicit scheme. Category edge inclusivity changes how exact-boundary values are labeled.

Further background: Carlson Trophic State Equations and Interpretation.

References

TSI Composite Average Calculator — tool.io
Carlson Trophic State Equations and Interpretation — North American Lake Management Society

Similar or alternative tools

TSI Carlson Chlorophyll Calculator
Chlorophyll is an algal-pigment proxy. Carlson’s empirical index relates its concentration to a continuous trophic-state scale.
Trophic Category Classifier
Trophic categories divide a continuous index using an explicit scheme. Category edge inclusivity changes how exact-boundary values are labeled.