adding tests + removing prints.

src/hinit.jl

@@ -7,8 +7,6 @@ function euler_first_guess(solver::AbstractDPSolver{T}, hmax::T, posneg::T) wher
         (abs(f0i)/sk)^2, (abs(yi)/sk)^2 # dnf, dny
     end
 
-    println("euler_first_guess: dnf = $dnf, dny = $dny")
-
     if (dnf <= 1.0e-10) || (dny <= 1.0e-10)
         h = 1.0e-6
     else
@@ -48,7 +46,6 @@ function hinit(
     the increment for explicit euler is small
     compared to the solution
     =#
-    println("hinit: y = $(solver.y), k1 = $(solver.k1), k2 = $(solver.k2), k3 = $(solver.k3)")
     h, dnf = euler_first_guess(solver, hmax, posneg)
 
     ###### Perform an explicit step

test/errors.jl

@@ -1,11 +1,13 @@
 using Test
 using DormandPrince:
     DP5Solver,
+    DP8Solver,
     Options,
     LARGER_NMAX_NEEDED,
     STEP_SIZE_BECOMES_TOO_SMALL
 
 using DormandPrince. DP5: dopri5
+using DormandPrince. DP8: dop853
 
 @testset "Larger nmax needed" begin
     solver = DP5Solver(
@@ -19,6 +21,17 @@ using DormandPrince. DP5: dopri5
     h, report = dopri5(solver, 2/0.0001, 0.1, 0.0)
     @test report.idid == LARGER_NMAX_NEEDED
 
+    solver = DP8Solver(
+        stiff_fcn,
+        0.0, # start at 0.0
+        [0.0001] # delta
+        ; maximum_allowed_steps=1
+    )
+
+
+    h, report = dop853(solver, 2/0.0001, 0.1, 0.0)
+    @test report.idid == LARGER_NMAX_NEEDED
+
 end
 
 @testset "Step size becomes too small" begin
@@ -32,4 +45,15 @@ end
 
     h, report = dopri5(solver, 2/0.0001, 0.1, 0.0)
     @test report.idid == STEP_SIZE_BECOMES_TOO_SMALL
+
+    solver = DP8Solver(
+        stiff_fcn,
+        0.0,
+        [0.0001]
+        ; uround=10000
+    )
+
+
+    h, report = dop853(solver, 2/0.0001, 0.1, 0.0)
+    @test report.idid == STEP_SIZE_BECOMES_TOO_SMALL
 end

test/stiff.jl

@@ -1,18 +1,19 @@
 using Test
-using DormandPrince: DP5Solver, integrate
+using DormandPrince: DP5Solver, DP8Solver, integrate
 
 function stiff_fcn(x, y, f) 
     f[1] = y[1]^2 - y[1]^3
 end
 
 @testset "Stiff ODE" begin
 
-    solver = DP5Solver(
-        stiff_fcn,
-        0.0, # start at 0.0
-        [0.0001] # initial value of delta
-    )
-
-    integrate(solver, 2/0.0001)
-
+    for SolverType in [DP5Solver, DP8Solver]
+        solver = SolverType(
+            stiff_fcn,
+            0.0,
+            [0.0001]
+        )
+
+        integrate(solver, 2/0.0001)
+    end    
 end