Merge pull request #482 from SciML/s/fix-substitute-dict

Fix substitution with Dict

Author: shashi

src/systems/jumps/jumpsystem.jl

@@ -233,7 +233,7 @@ function DiffEqJump.JumpProblem(js::JumpSystem, prob, aggregator; kwargs...)
     # handling parameter substition and empty param vecs
     p = (prob.p == DiffEqBase.NullParameters()) ? Operation[] : prob.p
     parammap  = map((x,y)->Pair(x(),y), parameters(js), p)
-    subber    = substituter(first.(parammap), last.(parammap))
+    subber    = substituter(parammap)
 
     majs = MassActionJump[assemble_maj(js, j, statetoid, subber, invttype) for j in eqs.x[1]]
     crjs = ConstantRateJump[assemble_crj(js, j, statetoid) for j in eqs.x[2]]

src/utils.jl

@@ -117,19 +117,12 @@ substitute(expr::Operation, s::Vector)
 Performs the substitution `Operation => val` on the `expr` Operation.
 """
 substitute(expr::Constant, s) = expr
-substitute(expr::Operation, s::Pair) = _substitute(expr, [s[1]], [s[2]])
-substitute(expr::Operation, dict::Dict) = _substitute(expr, keys(dict), values(dict))
-substitute(expr::Operation, s::Vector) = _substitute(expr, first.(s), last.(s))
+substitute(expr::Operation, s::Pair) = substituter([s[1] => s[2]])(expr)
+substitute(expr::Operation, s::Union{Vector, Dict}) = substituter(s)(expr)
 
-function _substitute(ks, vs)
-    expr -> _substitute(expr, Dict(map(Pair, map(to_symbolic, ks), map(to_symbolic, vs))))
-end
-
-function substituter(ks, vs)
-    dict = Dict(map(Pair, map(to_symbolic, ks), map(to_symbolic, vs)))
+function substituter(pairs)
+    dict = Dict(to_symbolic(k) => to_symbolic(v)  for (k, v) in pairs)
     expr -> to_mtk(SymbolicUtils.simplify(SymbolicUtils.substitute(expr, dict)))
 end
 
-_substitute(expr, ks, vs) = substituter(ks, vs)(expr)
-
 @deprecate substitute_expr!(expr,s) substitute(expr,s)

test/reactionsystem.jl

@@ -117,7 +117,7 @@ jumps[20] = VariableRateJump((u,p,t) -> p[20]*t*u[1]*binomial(u[2],2)*u[3], inte
 statetoid = Dict(convert(Variable,state) => i for (i,state) in enumerate(states(js)))
 parammap = map((x,y)->Pair(x(),y),parameters(js),pars)
 for i = 1:14
-  maj = MT.assemble_maj(js, js.eqs[i], statetoid, ModelingToolkit.substituter(first.(parammap), last.(parammap)),eltype(pars))
+  maj = MT.assemble_maj(js, js.eqs[i], statetoid, ModelingToolkit.substituter(parammap),eltype(pars))
   @test abs(jumps[i].scaled_rates - maj.scaled_rates) < 100*eps()
   @test jumps[i].reactant_stoch == maj.reactant_stoch
   @test jumps[i].net_stoch == maj.net_stoch

test/simplify.jl

@@ -29,3 +29,6 @@ d3 = Differential(x)(d2)
 
 @test simplified_expr(expand_derivatives(d3)) == :(0)
 @test simplified_expr(simplify(x^0)) == :(1)
+
+@test ModelingToolkit.substitute(2x + y == 1, Dict(x => 0.0, y => 0.0)).value === false
+@test ModelingToolkit.substitute(2x + y == 1, Dict(x => 0.0, y => 1.0)).value === true