PSATD: Implement First-Order Equations (#3466)

* Implement First-Order PSATD Equations

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Fix Unused Parameter Warning

* Fix RZ Build

* Fix Normalization of G to Match PML

* Add CI Test: 3D Uniform Plasma

* Cleaning

* Update 2D CI Checksums

* Update 3D CI Checksums

* Add F,G to CI Checksums of `uniform_plasma_multiJ`

* Allow User to Choose First-Order v. Second-Order

* Add WARPX_ALWAYS_ASSERT_WITH_MESSAGE

* Rename New Class `PsatdAlgorithmFirstOrder`

* Remove Inline Comment

* Update RZ CI Checksums

* Fix inline comment

* Use auxiliary variables to avoid divisions

* Use auxiliary variables to avoid divisions

* Make `nci_psatd_stability` dir and merge inputs

* Move all Galilean tests to `nci_psatd_stability`

* Fix CI

* Fix index for backward FFT of J

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/Source/Utils/WarpXAlgorithmSelection.H b/Source/Utils/WarpXAlgorithmSelection.H
index c3160cfad..936fd3d2b 100644
--- a/Source/Utils/WarpXAlgorithmSelection.H
+++ b/Source/Utils/WarpXAlgorithmSelection.H
@@ -84,6 +84,13 @@ struct GatheringAlgo {
     };
 };
 
+struct PSATDSolutionType {
+    enum {
+        FirstOrder = 0,
+        SecondOrder = 1
+    };
+};
+
 struct JInTime {
     enum {
         Constant = 0,
@@ -93,8 +100,8 @@ struct JInTime {
 
 struct RhoInTime {
     enum {
-        Linear = 1,
-        Quadratic = 2
+        Constant = 0,
+        Linear = 1
     };
 };