@@ -33,13 +33,12 @@ u(u_0,p,t,W_t)=u_0\exp((α-\frac{β^2}{2})t+βW_t)
3333
3434"""
3535prob_sde_linear = SDEProblem (SDEFunction (f_linear, σ_linear,
36- analytic = linear_analytic), σ_linear, 1 / 2 ,
36+ analytic = linear_analytic), 1 / 2 ,
3737 (0.0 , 1.0 ))
3838
3939linear_analytic_strat (u0, p, t, W) = @. (u0* exp (1.01 t + 0.87 W))
4040prob_sde_linear_stratonovich = SDEProblem (SDEFunction (f_linear, σ_linear,
41- analytic = linear_analytic_strat),
42- σ_linear, 1 / 2 , (0.0 , 1.0 ))
41+ analytic = linear_analytic_strat), 1 / 2 , (0.0 , 1.0 ))
4342f_linear_iip (du, u, p, t) = @. (du= 1.01 * u)
4443σ_linear_iip (du, u, p, t) = @. (du= 0.87 * u)
4544@doc doc"""
@@ -55,11 +54,9 @@ u(u_0,p,t,W_t)=u_0\exp((α-\frac{β^2}{2})t+βW_t)
5554```
5655"""
5756prob_sde_2Dlinear = SDEProblem (SDEFunction (f_linear_iip, σ_linear_iip,
58- analytic = linear_analytic),
59- σ_linear_iip, ones (4 , 2 ) / 2 , (0.0 , 1.0 ))
57+ analytic = linear_analytic), ones (4 , 2 ) / 2 , (0.0 , 1.0 ))
6058prob_sde_2Dlinear_stratonovich = SDEProblem (SDEFunction (f_linear_iip, σ_linear_iip,
61- analytic = linear_analytic_strat),
62- σ_linear_iip, ones (4 , 2 ) / 2 , (0.0 , 1.0 ))
59+ analytic = linear_analytic_strat), ones (4 , 2 ) / 2 , (0.0 , 1.0 ))
6360
6461f_cubic (u, p, t) = - 0.25 * u * (1 - u^ 2 )
6562σ_cubic (u, p, t) = 0.5 * (1 - u^ 2 )
@@ -76,7 +73,7 @@ and initial condition ``u_0=\frac{1}{2}``, with solution
7673u(u0,p,t,W_t)=\f rac{(1+u_0)\e xp(W_t)+u)0-1}{(1+u_0)\e xp(W_t)+1-u_0}
7774```
7875"""
79- prob_sde_cubic = SDEProblem (ff_cubic, σ_cubic, 1 / 2 , (0.0 , 1.0 ))
76+ prob_sde_cubic = SDEProblem (ff_cubic, 1 / 2 , (0.0 , 1.0 ))
8077
8178f_wave (u, p, t) = @. - 0.01 * sin (u) * cos (u)^ 3
8279σ_wave (u, p, t) = @. 0.1 * cos (u)^ 2
@@ -93,7 +90,7 @@ and initial condition ``u_0=1`` with solution
9390u(u_0,p,t,W_t)=\a rctan(\f rac{W_t}{10} + \t an(u_0))
9491```
9592"""
96- prob_sde_wave = SDEProblem (ff_wave, σ_wave, 1.0 , (0.0 , 1.0 ))
93+ prob_sde_wave = SDEProblem (ff_wave, 1.0 , (0.0 , 1.0 ))
9794
9895f_additive (u, p, t) = @. p[2 ] / sqrt (1 + t) - u / (2 * (1 + t))
9996σ_additive (u, p, t) = @. p[1 ] * p[2 ] / sqrt (1 + t)
@@ -113,7 +110,7 @@ and initial condition ``u_0=1`` with ``α=0.1`` and ``β=0.05``, with solution
113110u(u_0,p,t,W_t)=\f rac{u_0}{\s qrt{1+t}} + \f rac{β(t+αW_t)}{\s qrt{1+t}}
114111```
115112"""
116- prob_sde_additive = SDEProblem (ff_additive, σ_additive, 1.0 , (0.0 , 1.0 ), p)
113+ prob_sde_additive = SDEProblem (ff_additive, 1.0 , (0.0 , 1.0 ), p)
117114
118115f_additive_iip (du, u, p, t) = @. (du= p[2 ] / sqrt (1 + t) - u / (2 * (1 + t)))
119116σ_additive_iip (du, u, p, t) = @. (du= p[1 ] * p[2 ] / sqrt (1 + t))
@@ -123,7 +120,7 @@ p = ([0.1; 0.1; 0.1; 0.1], [0.5; 0.25; 0.125; 0.1115])
123120A multiple dimension extension of `additiveSDEExample`
124121
125122"""
126- prob_sde_additivesystem = SDEProblem (ff_additive_iip, σ_additive_iip, [1.0 ; 1.0 ; 1.0 ; 1.0 ],
123+ prob_sde_additivesystem = SDEProblem (ff_additive_iip, [1.0 ; 1.0 ; 1.0 ; 1.0 ],
127124 (0.0 , 1.0 ), p)
128125
129126function f_lorenz (du, u, p, t)
@@ -157,7 +154,7 @@ ff_nltest = SDEFunction(f_nltest, σ_nltest, analytic = analytic_nltest)
157154Runge–Kutta methods for numerical solution of stochastic differential equations
158155Tocino and Ardanuy
159156"""
160- prob_sde_nltest = SDEProblem (ff_nltest, σ_nltest, 1.0 , (0.0 , 10.0 ))
157+ prob_sde_nltest = SDEProblem (ff_nltest, 1.0 , (0.0 , 10.0 ))
161158
162159@doc doc"""
163160oval2ModelExample(;largeFluctuations=false,useBigs=false,noiseLevel=1)
@@ -404,7 +401,7 @@ Stiffness of Euler is determined by α+β²<1
404401Higher α or β is stiff, with α being deterministic stiffness and
405402β being noise stiffness (and grows by square).
406403"""
407- prob_sde_stiffquadito = SDEProblem (ff_stiff_quad_ito, stiff_quad_g, 0.5 , (0.0 , 3.0 ),
404+ prob_sde_stiffquadito = SDEProblem (ff_stiff_quad_ito, 0.5 , (0.0 , 3.0 ),
408405 (1.0 , 1.0 ))
409406
410407@doc doc"""
@@ -424,7 +421,7 @@ Stiffness of Euler is determined by α+β²<1
424421Higher α or β is stiff, with α being deterministic stiffness and
425422β being noise stiffness (and grows by square).
426423"""
427- prob_sde_stiffquadstrat = SDEProblem (ff_stiff_quad_strat, stiff_quad_g, 0.5 , (0.0 , 3.0 ),
424+ prob_sde_stiffquadstrat = SDEProblem (ff_stiff_quad_strat, 0.5 , (0.0 , 3.0 ),
428425 (1.0 , 1.0 ))
429426
430427@doc doc"""
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