LoopAnalyst (version 1.1-1)

feedback: Feedback of a Partially Specified System

Description

Computes the qualitative feedback of a partially specified system; where qualitative means direction: increases, decreases, no change, or ambiguous.

Usage

feedback(C)

Arguments

C

A (-1, 0 1) square matrix.

Value

• -1, 0, 1, or NA

Details

The supplied matrix is validated as a square (-1, 0, 1) matrix, and the sign-corrected product of system-spanning sets of disjunct loops is summed over all levels of feedback, and the result returned. Ambiguous results are returned as NA.

References

Puccia, C. J. and Levins, R. (1986) Qualitative Modeling of Complex Systems: An Introduction to Loop Analysis and Time Averaging. Cambridge: Harvard University Press.

See Also

make.cm.

Examples

## compute the feedback of a system
data(submatrix)
feedback(submatrix)