From d570816c04b6a4b244b722337299370678f92acc Mon Sep 17 00:00:00 2001
From: Brandon Talamini <talamini1@llnl.gov>
Date: Tue, 26 Jul 2022 22:06:52 -0700
Subject: [PATCH] Avoid superfluous copy of residual vector when applying
 preconditioner

The residual vector is changed from a jax-numpy array to a standard
numpy array before the preconditioner is applied. Now numpy is told
to avoid copying the residual data and instead re-use the buffer.
This should avoid overhead, especially for large vectors.
---
 optimism/SparseCholesky.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/optimism/SparseCholesky.py b/optimism/SparseCholesky.py
index ee6f64c6..e6e43584 100644
--- a/optimism/SparseCholesky.py
+++ b/optimism/SparseCholesky.py
@@ -51,7 +51,7 @@ def update(self, new_stiffness_func):
         
     def apply(self, b):
         if type(b) == type(np.array([])):
-            b = onp.array(b)
+            b = onp.array(b, copy=False)
         return self.Precond(b)