set default number of available devices to 4

src/elisa/util/misc.py

@@ -258,24 +258,23 @@ def get_parallel_number(n: int | None) -> int:
         The available number of parallel processes.
     """
     n_max = jax.local_device_count()
+    n_default = 4
 
     if n is None:
-        return n_max
+        return n_default
     else:
         n = int(n)
         if n <= 0:
-            raise ValueError(
-                f'number of parallel processes must be positive, got {n}'
-            )
+            raise ValueError(f"number of parallel processes must be positive, got {n}")
 
     if n > n_max:
         warnings.warn(
-            f'number of parallel processes ({n}) is more than the number of '
-            f'available devices ({jax.local_device_count()}), reset to '
-            f'{jax.local_device_count()}',
+            f"number of parallel processes ({n}) is more than the number of "
+            f"available devices ({n_max}), reset to "
+            f"{n_max}",
             Warning,
         )
-        n = jax.local_device_count()
+        n = n_max
 
     return n