add dict utility

Project.toml

@@ -1,7 +1,7 @@
 name = "MonteCarloMeasurements"
 uuid = "0987c9cc-fe09-11e8-30f0-b96dd679fdca"
 authors = ["baggepinnen <[email protected]>"]
-version = "1.0.13"
+version = "1.1.0"
 
 [deps]
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"

src/particles.jl

@@ -692,3 +692,29 @@ function LinearAlgebra.mul!(
     y
 end
 
+
+"""
+    particle_dict2dict_vec(dict)
+
+Take a dict that vaps keys to uncertain values, and return a vector of dicts where each dict has a single sample (particle) of the uncertain values. The length of the returned vector is the number of samples (particles) for all uncertain parameters. 
+"""
+function particle_dict2dict_vec(dict)
+    # check the validity of uncertain parameters
+    found_particle_numbers = Set{Int}()
+    uncertain_parameters = Set{Base.keytype(dict)}()
+    for (k, v) in dict
+        if v isa AbstractParticles
+            push!(found_particle_numbers, nparticles(v))
+            push!(uncertain_parameters, k)
+        end
+    end
+    if length(found_particle_numbers) > 1
+        error("The number of samples (particles) for all uncertain parameters must be the same, but I found $(found_particle_numbers)")
+    elseif isempty(found_particle_numbers)
+        return [dict] # not much to do here
+    end
+    N = only(found_particle_numbers)
+    map(1:N) do i
+        Dict(k => vecindex(v, i) for (k, v) in dict)
+    end
+end

test/runtests.jl

@@ -548,6 +548,12 @@ Random.seed!(0)
         @test p1 == p2
         @test nparticles(bootstrap(p, 10)) == 10
         @test_nowarn bootstrap([p; p])
+
+        dict = Dict(:a => p, :b => q, :c => 1)
+        dictvec = MonteCarloMeasurements.particle_dict2dict_vec(dict)
+        @test length(dictvec) == nparticles(p)
+        @test dictvec[1] == Dict(:a => p.particles[1], :b => q.particles[1], :c => 1)
+        @test dictvec[2] == Dict(:a => p.particles[2], :b => q.particles[2], :c => 1)
     end
 
     @time @testset "mutation" begin