From adf02cfbb823d6b33b769243c85ac801118d513c Mon Sep 17 00:00:00 2001
From: TAU-Reinier <122060945+TAU-Reinier@users.noreply.github.com>
Date: Thu, 7 Dec 2023 17:03:56 -0600
Subject: [PATCH] Use Field.copy on F in ZernikeFilter to prevent in-place
 modification

The line `Fout = F` did not create a copy of F, just a second reference, and the line `Fout.field *= _np.exp(-1j * Ph)` modified the object referenced by both Fout and F, so the input Field also came out filtered.
---
 LightPipes/zernike.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/LightPipes/zernike.py b/LightPipes/zernike.py
index 53d206d8..b325cb5b 100644
--- a/LightPipes/zernike.py
+++ b/LightPipes/zernike.py
@@ -204,10 +204,9 @@ def ZernikeFilter(F, j_terms, R):
         # Ph -= Ph_i
         Ph += Ph_i
     
-    Fout = F
+    Fout = Field.copy(F)
     Fout.field *= _np.exp(-1j * Ph)
-    # Fout = Field.copy(F)
-    # Fout = SubPhase(Ph, Fout)
+
     return Fout