Merge pull request #20 from isaacsas/jump-problems

add JumpProblems to library

Author: ChrisRackauckas

src/DiffEqProblemLibrary.jl

@@ -8,6 +8,7 @@ include("ode/ode_premade_problems.jl")
 include("dae_premade_problems.jl")
 include("dde_premade_problems.jl")
 include("sde_premade_problems.jl")
+include("jump_premade_problems.jl")
 
 #ODE Example Problems
 export prob_ode_linear, prob_ode_bigfloatlinear, prob_ode_2Dlinear,
@@ -45,4 +46,9 @@ export prob_dde_1delay, prob_dde_1delay_notinplace, prob_dde_1delay_scalar_notin
 # examples with vanishing state dependent delays
        prob_neves2, prob_dde_gatica
 
+# Jump Example Problems
+export prob_jump_dnarepressor, prob_jump_constproduct, prob_jump_nonlinrxs,
+# examples mixing mass action and constant rate jumps
+       prob_jump_osc_mixed_jumptypes
+
 end # module

src/jump_premade_problems.jl

@@ -0,0 +1,91 @@
+""" 
+    General structure to hold JumpProblem info. Needed since
+    the JumpProblem constructor requires the algorithm, so we 
+    don't create the JumpProblem here.
+"""
+struct JumpProblemNetwork 
+    network         # DiffEqBiological network
+    rates           # vector of rate constants or nothing
+    tstop           # time to end simulation
+    u0              # initial values
+    discrete_prob   # initialized discrete problem
+    prob_data       # additional problem data, stored as a Dict
+end
+
+"""
+    DNA negative feedback autoregulatory model. Protein acts as repressor.    
+"""
+rs = @reaction_network ptype begin
+    k1, DNA --> mRNA + DNA
+    k2, mRNA --> mRNA + P
+    k3, mRNA --> 0
+    k4, P --> 0
+    k5, DNA + P --> DNAR
+    k6, DNAR --> DNA + P
+end k1 k2 k3 k4 k5 k6
+rates = [.5, (20*log(2.)/120.), (log(2.)/120.), (log(2.)/600.), .025, 1.]
+tf = 1000.0
+u0 = [1,0,0,0]
+prob = DiscreteProblem(u0, (0.0, tf), rates)
+Nsims = 8000
+expected_avg = 5.926553750000000e+02
+prob_data = Dict("num_sims_for_mean" => Nsims, "expected_mean" => expected_avg)
+prob_jump_dnarepressor = JumpProblemNetwork(rs, rates, tf, u0, prob, prob_data)
+
+
+"""
+    Simple constant production with degradation example
+"""
+rs = @reaction_network pdtype begin
+    k1, 0 --> A
+    k2, A --> 0
+end k1 k2
+rates = [1000., 10.]
+tf = 1.0
+u0 = [0]
+prob = DiscreteProblem(u0, (0., tf), rates)
+Nsims = 16000
+expected_avg = t -> rates[1] / rates[2] .* ( 1. - exp.(-rates[2] * t))
+prob_data = Dict("num_sims_for_mean" => Nsims, "expected_mean_at_t" => expected_avg)
+prob_jump_constproduct = JumpProblemNetwork(rs, rates, tf, u0, prob, prob_data)
+
+
+"""
+    Example with a mix of nonlinear reactions, including third order
+"""
+rs = @reaction_network dtype begin
+    k1, 2A --> B
+    k2, B --> 2A 
+    k3, A + B --> C
+    k4, C --> A + B
+    k5, 3C --> 3A
+end k1 k2 k3 k4 k5
+rates = [1., 2., .5, .75, .25]
+tf = .01
+u0 = [200, 100, 150]
+prob = DiscreteProblem(u0, (0., tf), rates)
+Nsims = 32000
+expected_avg = 84.876015624999994
+prob_data = Dict("num_sims_for_mean" => Nsims, "expected_mean" => expected_avg)
+prob_jump_nonlinrxs = JumpProblemNetwork(rs, rates, tf, u0, prob, prob_data)
+
+
+"""
+    Oscillatory system, uses a mixture of jump types.
+"""
+rs = @reaction_network rnType  begin
+    0.01, (X,Y,Z) --> 0
+    hill(X,3.,100.,-4), 0 --> Y
+    hill(Y,3.,100.,-4), 0 --> Z
+    hill(Z,4.5,100.,-4), 0 --> X
+    hill(X,2.,100.,6), 0 --> R
+    hill(Y,15.,100.,4)*0.002, R --> 0
+    20, 0 --> S
+    R*0.005, S --> SP
+    0.01, SP + SP --> SP2
+    0.05, SP2 --> 0
+end
+u0 = [200.,60.,120.,100.,50.,50.,50.]  # Hill equations force use of floats!
+tf = 4000.
+prob = DiscreteProblem(u0, (0.,tf))
+prob_jump_osc_mixed_jumptypes = JumpProblemNetwork(rs, nothing, tf, u0, prob, nothing)