Reacting to new requirements on parameter setting from Solve IVP and fixing some other issues with order of set_integrator, set_initial_value and set_parameters. Fixes Issue #29.

Author: Wrzlprmft

jitcode/_jitcode.py

@@ -571,6 +571,7 @@ def set_integrator(self,name,nsteps=10**6,interpolate=True,**integrator_params):
 			* `"dopri5"` – Dormand’s and Prince’s explicit fifth-order method via `ode`
 			* `"RK45"` – Dormand’s and Prince’s explicit fifth-order method via `solve_ivp`
 			* `"dop853"` – DoP853 (explicit) via `ode`
+			* `"DOP853"` – DoP853 (explicit) via `solve_ivp`
 			* `"RK23"` – Bogacki’s and Shampine’s explicit third-order method via `solve_ivp`
 			* `"BDF"` – Implicit backward-differentiation formula via `solve_ivp`
 			* `"lsoda"` – LSODA (implicit) via `ode`
@@ -598,6 +599,7 @@ def set_integrator(self,name,nsteps=10**6,interpolate=True,**integrator_params):
 		self.generate_functions()
 
 		if info["backend"] == "ode":
+			self.initialise()
 			self.integrator = ODE_wrapper(self.f,self.jac)
 			self.integrator.set_integrator(
 					name,
@@ -611,26 +613,33 @@ def set_integrator(self,name,nsteps=10**6,interpolate=True,**integrator_params):
 			self.integrator = IVP(
 					name,
 					self.f,
-					self.jac,
+					initialiser = lambda: self.initialise(force=True),
+					jac = self.jac,
 					**integrator_params
 				)
 
-		# Restore state and params, if applicable:
+		# Restore state and time, if applicable:
 		try:
-			self.set_initial_value(old_integrator._y,old_integrator.t)
+			old_y = old_integrator._y
+			old_t = old_integrator.t
 		except (AttributeError,RuntimeError):
 			pass
+		else:
+			self.set_initial_value(old_y,old_t)
 
-	def initialise(self):
+	def initialise(self,force=False):
 		if self._initialise is not None:
-			self._initialise(
+			if len(self.control_par_values)==len(self.control_pars):
+				self._initialise(
 					*self.control_par_values,
 					*[callback for _,callback,_ in self.callback_functions]
 				)
+			elif force:
+				raise RuntimeError("Something needs parameters to be set. Try calling `set_parameters` earlier.")
 
 	def set_parameters(self,*args):
 		"""
-		Same as `set_f_params` and `set_jac_params` for SciPy’s ODE (both  sets of parameters are set simultaneuosly, because they should be the same anyway).
+		Same as `set_f_params` and `set_jac_params` for SciPy’s ODE (both sets of parameters are set simultaneuosly, because they should be the same anyway).
 		
 		The parameters can be passed as different arguments or as a list or other sequence.
 		"""
@@ -642,6 +651,9 @@ def set_parameters(self,*args):
 			if len(args)>1:
 				raise TypeError("Argument must either be a single sequence or multiple numbers.")
 
+		if len(self.control_par_values)!=len(self.control_pars):
+			raise ValueError("Number of values does not match number of control parameters.")
+		
 		self.initialise()
 
 	def set_f_params(self, *args):

jitcode/integrator_tools.py

@@ -40,12 +40,19 @@ class IVP_wrapper(object):
 	This is a wrapper around the integrators from scipy.integrate.solve_ivp making them work like scipy.integrate.ode (mostly).
 	"""
 
-	def __init__(self,name,f,jac=None,**kwargs):
+	def __init__(
+			self,
+			name,
+			f, jac=None,
+			initialiser = lambda:None,
+			**kwargs
+		):
 		info = integrator_info(name)
 		self.ivp_class = info["integrator"]
 		self.f = f
 		self.jac = jac
 		self.wants_jac = info["wants_jac"]
+		self.initialiser = initialiser
 
 		# Dictionary to be passed as arguments to the integrator and store stuff
 		self.kwargs = {
@@ -76,6 +83,7 @@ def try_to_initiate(self):
 				"t0" in self.kwargs and
 				"y0" in self.kwargs
 			):
+			self.initialiser()
 			self.backend = self.ivp_class(**self.kwargs)
 
 	def set_initial_value(self, initial_value, time=0.0):

tests/test_order.py

@@ -0,0 +1,58 @@
+from jitcode import jitcode
+from symengine import Symbol
+from itertools import permutations
+
+p = Symbol('p')
+
+f = [1/p]
+
+for integrator in ["dopri5","RK45"]:
+	def set_integrator(ODE):
+		ODE.set_integrator(integrator)
+	
+	def set_parameters(ODE):
+		ODE.set_parameters(1)
+	
+	def set_initial_value(ODE):
+		ODE.set_initial_value([0], 0)
+	
+	at_east_one_working_order = False
+	for functions in permutations([set_integrator,set_parameters,set_initial_value]):
+		ODE = jitcode(f, control_pars=[p], verbose=False)
+		try:
+			for function in functions:
+				function(ODE)
+		except RuntimeError as exception:
+			assert str(exception).startswith("Something needs parameters to be set")
+		else:
+			assert abs(ODE.integrate(1.)-1) < 1e-8
+			at_east_one_working_order = True
+		
+		print( ".", end="", flush=True )
+	assert at_east_one_working_order
+
+f_2 = [1]
+
+for integrator in ["dopri5","RK45"]:
+	def set_integrator(ODE):
+		ODE.set_integrator(integrator)
+	
+	def set_initial_value(ODE):
+		ODE.set_initial_value([0], 0)
+	
+	at_east_one_working_order = False
+	for functions in permutations([set_integrator,set_initial_value]):
+		ODE = jitcode(f_2, verbose=False)
+		try:
+			for function in functions:
+				function(ODE)
+		except RuntimeError as exception:
+			assert str(exception).startswith("Something needs parameters to be set")
+		else:
+			assert abs(ODE.integrate(1.)-1) < 1e-8
+			at_east_one_working_order = True
+		
+		print( ".", end="", flush=True )
+	assert at_east_one_working_order
+
+print("")