foxleg {RGeostats} R Documentation

## Optimize of a set of parameters

### Description

Optimize a set of parameters

### Usage

```foxleg(formula, start = NA, lower = NA, upper = NA, equal = NA, weights = NA,
maxiter = 1000, tolstop = 1.e-5, epsdelta = 1.e-5, delta=1,
verbose = FALSE)
```

### Arguments

 `formula` a nonlinear model formula (including variables and parameters) which describes the link between a response variable, some explanatory variables and the parameters to optimize. `start` a named list or named numeric vector of starting estimates. When the initial value is missing for some parameters, they are initialized with a very cheap guess. `lower` a named list or named numeric vector of lower bounds for the set of parameters. If they are not defined for some parameters, the corresponding lower bounds are set to -infinity. `upper` a named list or named numeric vector of upper bounds for the set of parameters. If they are not defined for some parameters, the corresponding lower bounds are set to +infinity. `equal` a named list or named numeric vector of equalities for the set of parameters. `weights` Set of weights attached to each datum. If not provided, the weights are defaulted to 1 `maxiter` Maximum number of iterations `tolstop` Tolerance for the distance between the experiment and the model. `epsdelta` Tolerance for the direction increment used in the gradient search `delta` Delta value `verbose` Verbose flag.

### Value

The list containing the optimal values for each parameter.

### Examples

```# Generate two initial vectors of 100 values (with some randomization)
x <- 2 + rnorm(100)
y <- exp(-0.5 * x) + 0.1 * rnorm(100)
res<- foxleg(y~exp(-a*x)+b)
xp <- seq(-1,6.,0.01)
yp <- exp(-res\$a * xp) + res\$b
plot(x,y)
lines(xp,yp)
```

[Package RGeostats version 11.1.2 Index]