baro5 function

The modified baro5 function

'baro5' allows specification of the baroreflex 5-parameter dose response function, under various constraints on the parameters.

baro5(fixed = c(NA, NA, NA, NA, NA), names = c("b1", "b2", "c", "d", "e"),
  method = c("1", "2", "3", "4"), ssfct = NULL)

Arguments

• fixed: numeric vector. Specifies which parameters are fixed and at what value they are fixed. NAs for parameter that are not fixed.
• names: a vector of character strings giving the names of the parameters (should not contain ":"). The order of the parameters is: b1, b2, c, d, e (see under 'Details').
• method: character string indicating the self starter function to use.
• ssfct: a self starter function to be used.

Details

The five-parameter function given by the expression

If the difference between the parameters b1 and b2 is different from 0 then the function is asymmetric.

Returns

The value returned is a list containing the nonlinear model function, the self starter function and the parameter names.

References

Ricketts, J. H. and Head, G. A. (1999) A five-parameter logistic equation for investigating asymmetry of curvature in baroreflex studies. Am. J. Physiol. (Regulatory Integrative Comp. Physiol. 46), 277 , 441--454.

Author(s)

Christian Ritz

Note

See the example for the dataset heartrate.