From c79bd51f7006021e514749a53ba89ae1732cc22e Mon Sep 17 00:00:00 2001
From: Kipton Barros <kbarros@gmail.com>
Date: Wed, 15 Nov 2023 08:31:12 -0700
Subject: [PATCH] Print an error if non-positive dt is detected

---
 src/Integrators.jl    | 10 ++++++++--
 test/test_jet.jl      |  4 ++--
 test/test_samplers.jl |  4 ++--
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/Integrators.jl b/src/Integrators.jl
index f32e9e1f8..92cbf8496 100644
--- a/src/Integrators.jl
+++ b/src/Integrators.jl
@@ -21,7 +21,10 @@ mutable struct Langevin
     kT  :: Float64
 end
 
-Langevin(Δt; λ, kT) = Langevin(Δt, λ, kT)
+function Langevin(Δt; λ, kT)
+    Δt <= 0 && error("Select positive Δt")
+    return Langevin(Δt, λ, kT)
+end
 
 Base.copy(dyn::Langevin) = Langevin(dyn.Δt, dyn.λ, dyn.kT)
 
@@ -41,7 +44,10 @@ mutable struct ImplicitMidpoint
     atol :: Float64
 end
 
-ImplicitMidpoint(Δt; atol=1e-12) = ImplicitMidpoint(Δt, atol)
+function ImplicitMidpoint(Δt; atol=1e-12)
+    Δt <= 0 && error("Select positive Δt")
+    return ImplicitMidpoint(Δt, atol)
+end
 
 
 
diff --git a/test/test_jet.jl b/test/test_jet.jl
index 9854821bf..08c1dd2d5 100644
--- a/test/test_jet.jl
+++ b/test/test_jet.jl
@@ -16,7 +16,7 @@
         sampler = LocalSampler(kT=0.2; propose)
         @test_opt step!(sys, sampler)
 
-        langevin = Langevin(0.01, kT=0.2, λ=0.1)
+        langevin = Langevin(0.01; kT=0.2, λ=0.1)
         @test_opt step!(sys, langevin)
 
         integrator = ImplicitMidpoint(0.01)
@@ -48,7 +48,7 @@ end
         step!(sys, sampler)
         @test 0 == @allocated step!(sys, sampler)
 
-        langevin = Langevin(0.01, kT=0.2, λ=0.1)
+        langevin = Langevin(0.01; kT=0.2, λ=0.1)
         step!(sys, langevin)
         @test 0 == @allocated step!(sys, langevin)
 
diff --git a/test/test_samplers.jl b/test/test_samplers.jl
index 84f66c226..783161edc 100644
--- a/test/test_samplers.jl
+++ b/test/test_samplers.jl
@@ -72,7 +72,7 @@
         collect_dur = 100.0
 
         sys = su3_anisotropy_model(; D, L, seed=0)
-        langevin = Langevin(Δt; kT=0.0, λ)
+        langevin = Langevin(Δt; kT=0, λ)
 
         for kT in kTs
             langevin.kT = kT
@@ -96,7 +96,7 @@
         collect_dur = 200.0
 
         sys = su5_anisotropy_model(; D, L, seed=0)
-        langevin = Langevin(Δt; kT=0.0, λ)
+        langevin = Langevin(Δt; kT=0, λ)
 
         for kT ∈ kTs
             langevin.kT = kT