DormandPrince45 constructor
DormandPrince45(.ode)
.ode | an ODE object |
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# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ base class: KeplerVerlet.R setClass("KeplerDormandPrince45", slots = c( GM = "numeric", odeSolver = "DormandPrince45", counter = "numeric" ), contains = c("ODE") ) setMethod("initialize", "KeplerDormandPrince45", function(.Object, ...) { .Object@GM <- 4 * pi * pi # gravitation constant times combined mass .Object@state <- vector("numeric", 5) # x, vx, y, vy, t .Object@odeSolver <- DormandPrince45(.Object) .Object@counter <- 0 return(.Object) })#> [1] "initialize"setMethod("doStep", "KeplerDormandPrince45", function(object, ...) { object@odeSolver <- step(object@odeSolver) object@state <- object@odeSolver@ode@state object })#> [1] "doStep"setMethod("getTime", "KeplerDormandPrince45", function(object, ...) { return(object@state[5]) })#> [1] "getTime"setMethod("getEnergy", "KeplerDormandPrince45", function(object, ...) { ke <- 0.5 * (object@state[2] * object@state[2] + object@state[4] * object@state[4]) pe <- -object@GM / sqrt(object@state[1] * object@state[1] + object@state[3] * object@state[3]) return(pe+ke) })#> [1] "getEnergy"setMethod("init", "KeplerDormandPrince45", function(object, initState, ...) { object@state <- initState # call init in AbstractODESolver object@odeSolver <- init(object@odeSolver, getStepSize(object@odeSolver)) object@counter <- 0 object })#> [1] "init"setReplaceMethod("init", "KeplerDormandPrince45", function(object, ..., value) { object@state <- value # call init in AbstractODESolver object@odeSolver <- init(object@odeSolver, getStepSize(object@odeSolver)) object@counter <- 0 object })#> [1] "init<-"setMethod("getRate", "KeplerDormandPrince45", function(object, state, ...) { # Computes the rate using the given state. r2 <- state[1] * state[1] + state[3] * state[3] # distance squared r3 <- r2 * sqrt(r2) # distance cubed object@rate[1] <- state[2] object@rate[2] <- (- object@GM * state[1]) / r3 object@rate[3] <- state[4] object@rate[4] <- (- object@GM * state[3]) / r3 object@rate[5] <- 1 # time derivative object@counter <- object@counter + 1 object@rate })#> [1] "getRate"setMethod("getState", "KeplerDormandPrince45", function(object, ...) { # Gets the state variables. return(object@state) })#> [1] "getState"setReplaceMethod("setSolver", "KeplerDormandPrince45", function(object, value) { object@odeSolver <- value object })#> [1] "setSolver<-"# constructor KeplerDormandPrince45 <- function() { kepler <- new("KeplerDormandPrince45") return(kepler) }