make.wfm {LoopAnalyst}R Documentation

Compute the Weighted Feedback Matrix

Description

Validates a community matrix and computes its associated weighted feedback matrix.

Usage

make.wfm(CM, status=FALSE, digits=1)

Arguments

CM A valid community matrix.
status Switches on an element-by-element progress indicator when set to TRUE. Set to FALSE by default.
digits Indicates precision for elements in the weighted feedback matrix. By default, this is set to 1 significant digit.

Details

The supplied matrix is validated as a community matrix, and the weighted feedback matrix is computed. Each element is equal to the corresponding element of the adjoint of the negative community matrix divided by the corresponding element of the total feedback matrix T. Resulting values range from -1.0 to 1.0, with values of magnitude of 0.5 or greater indicating that positive or negative feedback is expected to dominate (as per the sign of the value). Values of -1 or 1 are unambiguous predictions, regardless of the quantitative magnitude of the system's linkages. Unresolvably ambiguous effects are represented by values between -0.5 and 0.5.

Value

The weighted feedback matrix for a community matrix

Author(s)

Alexis Dinno http://www.doyenne.com/LoopAnalyst/

References

Dambacher, J. M., et al. (2003) Qualitative stability and ambiguity in model ecosystems. The American Naturalist, 161(6),876-888

Dambacher, J. M. and Li, H. W. and Rossignol, P. A. (2002) Relevance of community structure in assessing indeterminacy of ecological predictions. Ecology, 83(5),1372-1385

See Also

make.cem, make.adjoint, and make.T.

Examples

## compute weighted feedback matrix
data(community.matrix)
make.wfm(community.matrix)

[Package LoopAnalyst version 1.1-0 Index]