hill_utils: Functions to solve the Hill model
In daynefiler/tcpl: ToxCast Data Analysis Pipeline

Description Usage Arguments Details Examples

These functions solve for Hill model parameters.

tcplHillACXX(XX, tp, ga, gw, bt = 0)

tcplHillConc(val, tp, ga, gw, bt = 0)

tcplHillVal(logc, tp, ga, gw, bt = 0)

`XX`	Numeric, the activity level (percentage of the top value)
`tp`	Numeric, the top value from the Hill model
`ga`	Numeric, the logAC50 value from the Hill model
`gw`	Numeric, the Hill coefficient from the Hill model
`bt`	Numierc, the bottom value from the Hill model
`val`	Numeric, the activity value
`logc`	Numeric, the log concentration

tcplHillVal computes the value of the Hill model for a given log concentration.

tcplHillACXX computes the activity concentration for a Hill model for a given activity level.

tcplHillConc computes the Hill model concentration for a given value.

## The following code gives examples for a Hill model with a top of 50, 
## bottom of 0, AC50 of 1 and Hill coefficient of 1.
## tcplHillVal calculates activity value given a concentration. tcplHillVal
## will return the tp/2 when logc equals ga:
tcplHillVal(logc = 1, tp = 50, ga = 1, gw = 1, bt = 0)

## Here, tcplHillConc returns the concentration where the value equals 20
tcplHillConc(val = 20, tp = 50, ga = 1, gw = 1, bt = 0)

## Note how this differs from tcplHillACXX:
tcplHillACXX(XX = 20, tp = 50, ga = 1, gw = 1, bt = 0)

## tcplHillACXX is based on the top value and allows the user to calculate 
## specifc activity concentrations based on a percentage of the top value

## For example, we can calculate the value for the concentration 0.25, then
## use that value to check the other two functions.

value <- tcplHillVal(logc = 0.25, tp = 50, ga = 1, gw = 1, bt = 0)
c1 <- tcplHillConc(val = value, tp = 50, ga = 1, gw = 1, bt = 0)
c2 <- tcplHillACXX(XX = value/50*100, tp = 50, ga = 1, gw = 1, bt = 0)
all.equal(0.25, c1, c2)

## Notice, the value had to be transformed to a percentage of the top value
## when using tcplHillACXX