inst/doc/linear_chain.R

In GillespieSSA: Gillespie's Stochastic Simulation Algorithm (SSA)

## ---- setseed, echo=FALSE-----------------------------------------------------
set.seed(1)
knitr::opts_chunk$set(fig.width = 8, fig.height = 6)

## -----------------------------------------------------------------------------
library(GillespieSSA)

## -----------------------------------------------------------------------------
parms <- c(c = 1)                # Rate parameter
M <- 50                          # Number of chain reactions
simName <- "Linear Chain System" # Simulation name
tf <- 5                          # Final time

## -----------------------------------------------------------------------------
x0 <- c(1000, rep(0, M)) 
names(x0) <- paste0("x", seq_len(M+1))

## -----------------------------------------------------------------------------
nu <- matrix(rep(0, M * (M+1)), ncol = M)
nu[cbind(seq_len(M), seq_len(M))] <- -1
nu[cbind(seq_len(M)+1, seq_len(M))] <- 1

## -----------------------------------------------------------------------------
a <- paste0("c*x", seq_len(M))

## ----direct-------------------------------------------------------------------
set.seed(1)
out <- ssa(
  x0 = x0,
  a = a,
  nu = nu,
  parms = parms,
  tf = tf,
  method = ssa.d(),
  simName = simName,
  verbose = FALSE,
  consoleInterval = 1
) 
ssa.plot(out, show.title = TRUE, show.legend = FALSE)

## ----etl----------------------------------------------------------------------
set.seed(1)
out <- ssa(
  x0 = x0,
  a = a,
  nu = nu,
  parms = parms,
  tf = tf,
  method = ssa.etl(tau = .1),
  simName = simName,
  verbose = FALSE,
  consoleInterval = 1
) 
ssa.plot(out, show.title = TRUE, show.legend = FALSE)

## ----btl----------------------------------------------------------------------
set.seed(1)
out <- ssa(
  x0 = x0,
  a = a,
  nu = nu,
  parms = parms,
  tf = tf,
  method = ssa.btl(f = 50),
  simName = simName,
  verbose = FALSE,
  consoleInterval = 1
) 
ssa.plot(out, show.title = TRUE, show.legend = FALSE)

## ----otl----------------------------------------------------------------------
set.seed(1)
out <- ssa(
  x0 = x0,
  a = a,
  nu = nu,
  parms = parms,
  tf = tf,
  method = ssa.otl(),
  simName = simName,
  verbose = FALSE,
  consoleInterval = 1
) 
ssa.plot(out, show.title = TRUE, show.legend = FALSE)