LDEsysMat {nlme} | R Documentation |

## Generate system matrix for LDEs

### Description

Generate the system matrix for the linear differential equations
determined by a compartment model.

### Usage

LDEsysMat(pars, incidence)

### Arguments

`pars` |
a numeric vector of parameter values. |

`incidence` |
an integer matrix with columns named `From` ,
`To` , and `Par` . Values in the `Par` column must
be in the range 1 to `length(pars)` .
Values in the `From`
column must be between 1 and the number of compartments.
Values in the `To`
column must be between 0 and the number of compartments. |

### Details

A compartment model describes material transfer between `k`

in a system of `k`

compartments to a linear system of differential
equations. Given a description of the system and a vector of parameter
values this function returns the system matrix.

This function is intended for use in a general system for solving
compartment models, as described in Bates and Watts (1988).

### Value

A `k`

by `k`

numeric matrix.

### Author(s)

Douglas Bates bates@stat.wisc.edu

### References

Bates, D. M. and Watts, D. G. (1988), *Nonlinear Regression
Analysis and Its Applications*, Wiley, New York.

### Examples

# incidence matrix for a two compartment open system
incidence <-
matrix(c(1,1,2,2,2,1,3,2,0), ncol = 3, byrow = TRUE,
dimnames = list(NULL, c("Par", "From", "To")))
incidence
LDEsysMat(c(1.2, 0.3, 0.4), incidence)

[Package

*nlme* version 3.1-57

Index]