logpolynomial_model: logpolynomial_model

In tbgitoo/rheologyEvaluation: rheologyEvaluation

Description

Evaluation of a polynomial model with an offset (polynomial_model) for the G' values; returns the log value for x>c0 and penalty negative value for x<=c0. The idea is that if the polymer concentration is smaller than the critical concentration c0, the suspension is liquid and we return G'=0, otherwise it's a polynomial function of x-c0 with exponent n and coefficient A. The logarithmic form is for fitting purposes

Usage

logpolynomial_model(x, A, c0, n,penalty_factor_below_offset=10)

Arguments

x	The variable for the polynomial model
A	Proportionality constant for the polynomial relation
c0	Offset for the polynomial model
n	Exponent for the polynomial relation
penalty_factor_below_offset	Factor for being able to return a value even when x is below c0

Value

log(A*(x-c0)^n) for x>c0, penalty_factor_below_offset*(A*(-x-c0)^n) for x<c0

Author(s)

Thomas Braschler

Examples

x=seq(from=0,to=50,length.out=200)
logGprimeModel = logpolynomial_model(x,1,20,3,penalty_factor_below_offset=NA)
plot(x,exp(logGprimeModel),type="b",xlab="Polymer concentration",log="y",ylab="Model G' value")

tbgitoo/rheologyEvaluation documentation built on March 19, 2021, 8 p.m.