Exponential dose-response function

Similar parameterisation to the Emax model but with non-asymptotic maximal effect (Emax). Can fit a 1-parameter (Emax only) or 2-parameter model (includes onset parameter that controls the curvature of the dose-response relationship)

dexp(emax = "rel", onset = NULL, p.expon = FALSE)

Arguments

emax

Pooling for Emax parameter. Can take "rel", "common", "random" or be assigned a numeric value (see details).

onset

Pooling for onset parameter. Can take "rel", "common", "random" or be assigned a numeric value (see details).

p.expon

A logical object to indicate whether ed50 and hill parameters should be expressed within the dose-response function on an exponential scale

Value

An object of class("dosefun")

Details

1-parameter model: \(emax\times{(1-exp(-x))}\)

2-parameter model: \(emax\times{(1-exp(onset*-x))}\)

where emax is the maximum efficacy of an agent and rate is the speed

Dose-response parameter arguments:

Argument	Model specification
"rel"	Implies that relative effects should be pooled for this dose-response parameter separately for each agent in the network.
"common"	Implies that all agents share the same common effect for this dose-response parameter.
"random"	Implies that all agents share a similar (exchangeable) effect for this dose-response parameter. This approach allows for modelling of variability between agents.
numeric()	Assigned a numeric value, indicating that this dose-response parameter should not be estimated from the data but should be assigned the numeric value determined by the user. This can be useful for fixing specific dose-response parameters (e.g. Hill parameters in Emax functions) to a single value.

References

There are no references for Rd macro \insertAllCites on this help page.

Examples

# Single parameter exponential function is default
dexp()
#> $name
#> [1] "exp"
#> 
#> $fun
#> ~emax * (1 - exp(-dose))
#> <environment: 0x55c46281ff18>
#> 
#> $p.expon
#> [1] FALSE
#> 
#> $params
#> [1] "emax"
#> 
#> $nparam
#> [1] 1
#> 
#> $jags
#> [1] "s.beta.1[agent[i,k]] * (1 - exp(- dose[i,k]))"
#> 
#> $apool
#>  emax 
#> "rel" 
#> 
#> $bname
#>     emax 
#> "beta.1" 
#> 
#> attr(,"class")
#> [1] "dosefun"

# Two parameter exponential function
dexp(onset="rel")
#> $name
#> [1] "exp"
#> 
#> $fun
#> ~emax * (1 - exp(onset * -dose))
#> <environment: 0x55c460550a80>
#> 
#> $p.expon
#> [1] FALSE
#> 
#> $params
#> [1] "emax"  "onset"
#> 
#> $nparam
#> [1] 2
#> 
#> $jags
#> [1] "s.beta.1[agent[i,k]] * (1 - exp(s.beta.2[agent[i,k]] * - dose[i,k]))"
#> 
#> $apool
#>  emax onset 
#> "rel" "rel" 
#> 
#> $bname
#>     emax    onset 
#> "beta.1" "beta.2" 
#> 
#> attr(,"class")
#> [1] "dosefun"