pm now accept pytrees

jaxpm/pm.py

@@ -7,7 +7,7 @@ from jaxpm.growth import (dGf2a, dGfa, growth_factor, growth_factor_second,
 from jaxpm.kernels import (PGD_kernel, fftk, gradient_kernel,
                            invlaplace_kernel, longrange_kernel)
 from jaxpm.painting import cic_paint, cic_paint_dx, cic_read, cic_read_dx
-
+import jax
 
 def pm_forces(positions,
               mesh_shape=None,
@@ -51,9 +51,11 @@ def pm_forces(positions,
     pot_k = delta_k * invlaplace_kernel(kvec) * longrange_kernel(
         kvec, r_split=r_split)
     # Computes gravitational forces
-    forces = jnp.stack([
+    forces = [
         read_fn(ifft3d(-gradient_kernel(kvec, i) * pot_k),positions
-        ) for i in range(3)], axis=-1) # yapf: disable
+        ) for i in range(3)]
+
+    forces = jax.tree.map(lambda x ,y ,z : jnp.stack([x,y,z], axis=-1), forces[0], forces[1], forces[2])
 
     return forces
 
@@ -71,8 +73,8 @@ def lpt(cosmo,
     """
     paint_absolute_pos = particles is not None
     if particles is None:
-        particles = jnp.zeros_like(initial_conditions,
-                                   shape=(*initial_conditions.shape, 3))
+        particles = jax.tree.map(lambda ic : jnp.zeros_like(ic,
+                                   shape=(*ic.shape, 3)) , initial_conditions)
 
     a = jnp.atleast_1d(a)
     E = jnp.sqrt(jc.background.Esqr(cosmo, a))
@@ -172,8 +174,7 @@ def make_ode_fn(mesh_shape,
     return nbody_ode
 
 
-def make_diffrax_ode(cosmo,
-                     mesh_shape,
+def make_diffrax_ode(mesh_shape,
                      paint_absolute_pos=True,
                      halo_size=0,
                      sharding=None):
@@ -183,6 +184,7 @@ def make_diffrax_ode(cosmo,
         state is a tuple (position, velocities)
         """
         pos, vel = state
+        cosmo = args
 
         forces = pm_forces(pos,
                            mesh_shape=mesh_shape,
@@ -196,7 +198,7 @@ def make_diffrax_ode(cosmo,
         # Computes the update of velocity (kick)
         dvel = 1. / (a**2 * jnp.sqrt(jc.background.Esqr(cosmo, a))) * forces
 
-        return jnp.stack([dpos, dvel])
+        return jax.tree.map(lambda dp , dv : jnp.stack([dp, dv],axis=0), dpos, dvel)
 
     return nbody_ode