Package jline.solvers.fluid.petri

Class PetriTerms

java.lang.Object
jline.solvers.fluid.petri.PetriTerms
public class PetriTerms extends Object
Event-based representation of the fluid marking process of a stochastic Petri net. Java twin of the MATLAB fluid_petri_terms.

A GSPN is already a density-dependent Markov population process, which is the object the moment-closure family of SolverFluid is built on: the marking is the population, a transition mode is a reaction, its incidence column is the jump, and the rate law lambda*min(enabling degree, servers) is the same min() non-linearity the min-normal closure exists to smooth. Nothing about the closure changes here; only where the drift comes from. 

    dx/dt = D * r(x, Sigma, phi, mu)

THE STATE, x = [ m ; y ].

  • m(p,k) token mass of class k at place p. One coordinate per (place, class) pair some arc touches, the initial marking loads, or a Source feeds; a pair nothing reaches is dropped rather than carried as a null direction of the Newton system.
  • y(j,h) the number of mode-j servers running in phase h, for a mode whose firing time has more than one phase. Their SUM is not free: the ENABLE synchronization latches it instantaneously to min(enabling degree, servers), so the latch is an ALGEBRAIC row with one free-sign unknown mu_j and the phase split evolves differentially. CARRYING THE DISTRIBUTION INSTEAD OF THE COUNT LOOKS TIDIER AND IS WRONG: the resulting equation is missing a term and agrees with the count form only AT a fixed point.

There is no Source coordinate: an exogenous arrival is a CONSTANT-propensity event depositing one token, as it is in the NRM SPN runner. There is no Sink coordinate either: a firing arc into a sink is mass leaving the net.

THE EVENTS, one column of D each: kind 1 a firing of mode j out of phase h into phase h'; kind 2 an internal phase change; kind 3 an exogenous arrival; kind 4 a firing of an IMMEDIATE mode, at the algebraic flow phi_j; kind 5 the server latch of a multi-phase mode, at the free-sign unknown mu_j; kind 6 the FLUID FLOW of mode j into (or out of) fluid place c, a unit column on the level f(c) signed by the direction of the flow, at |rate| per running server. A flow is DETERMINISTIC: it enters the drift and its Jacobian but not the diffusion. An impulse is not a column of its own; it is the fluid entry of the mode's firing column, so it is a stochastic jump.

A FLUID PLACE (FSPN) takes no marking coordinate: its level f(c) is one coordinate per fluid place, appended after the phase block.

  • Field Details

    • M

      public int M

    • K

      public int K

    • I

      public int I

    • places

      public List<Integer> places

    • transitions

      public List<Integer> transitions

    • fluidPlaces

      public List<Integer> fluidPlaces
      Fluid places (node indices), their level coordinates, bounds, initial levels, stations and names.

    • nf

      public int nf

    • fidx

      public int[] fidx
      node -> level coordinate, -1 for a node that is not a fluid place.

    • fluidSlot

      public int[] fluidSlot

    • fluidCap

      public double[] fluidCap

    • fluidInit

      public double[] fluidInit

    • fluidStation

      public int[] fluidStation

    • fluidName

      public String[] fluidName

    • flowCol

      public int[] flowCol
      The deterministic fluid flow columns (kind 6).

    • namesNode

      public List<String> namesNode

    • nstate

      public int nstate

    • nm

      public int nm

    • pidx

      public int[][] pidx
      (node, class) -> state coordinate, -1 where the pair carries none.

    • coordNode

      public int[] coordNode

    • coordClass

      public int[] coordClass

    • coordStation

      public int[] coordStation

    • modes

      public List<PetriMode> modes

    • timedIdx

      public List<Integer> timedIdx

    • immIdx

      public List<Integer> immIdx

    • D

      public Matrix D

    • rateBase

      public double[] rateBase

    • nev

      public int nev

    • evKind

      public int[] evKind

    • evMode

      public int[] evMode

    • evPhase

      public int[] evPhase

    • evTo

      public int[] evTo

    • evStation

      public int[] evStation

    • evClass

      public int[] evClass

    • evFlow

      public int[] evFlow
      Kind 6: the flow's position in its mode's flowSlot; 0 for every other kind.

    • immCol

      public int[] immCol

    • latchCol

      public int[] latchCol

    • stochCol

      public int[] stochCol
      The DIFFUSION counts the stochastic events only: an immediate flow and a server latch are both the limit of an infinitely fast mechanism whose fluctuation is slaved, not a Poisson stream with an intensity.

    • latchMode

      public List<Integer> latchMode

    • covIdx

      public int[] covIdx
      THE COVARIANCE COVERS EVERY COORDINATE, phases included: the rate of a multi-phase mode is linear in y and reads no marking, so dropping the phases would sever that mode's whole restoring force.

    • covPairs

      public int[][] covPairs

    • npair

      public int npair

    • pairIndex

      public int[][] pairIndex
      (a,b) -> closure unknown index, symmetric, -1 where the drift never reads it.

    • immColOf

      public int[] immColOf

    • consumers

      public Map<Integer,List<Integer>> consumers

    • consumerW

      public Map<Integer,List<Double>> consumerW

    • producers

      public Map<Integer,List<Integer>> producers

    • x0

      public double[] x0

    • m0full

      public double[][] m0full

    • options

      public SolverOptions options

  • Constructor Details

    • PetriTerms

      public PetriTerms()

  • Method Details