From bdf677825c422e47832d0282954769f390cd58fd Mon Sep 17 00:00:00 2001
From: Christoph Lehner <christoph@lhnr.de>
Date: Fri, 12 Jul 2024 15:48:40 +0200
Subject: [PATCH] missing files

---
 .../ad/reverse/foundation/matrix/__init__.py  | 19 ++++++++
 lib/gpt/ad/reverse/foundation/matrix/exp.py   | 43 +++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 lib/gpt/ad/reverse/foundation/matrix/__init__.py
 create mode 100644 lib/gpt/ad/reverse/foundation/matrix/exp.py

diff --git a/lib/gpt/ad/reverse/foundation/matrix/__init__.py b/lib/gpt/ad/reverse/foundation/matrix/__init__.py
new file mode 100644
index 00000000..1d6d9368
--- /dev/null
+++ b/lib/gpt/ad/reverse/foundation/matrix/__init__.py
@@ -0,0 +1,19 @@
+#
+#    GPT - Grid Python Toolkit
+#    Copyright (C) 2023  Christoph Lehner (christoph.lehner@ur.de, https://github.com/lehner/gpt)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation; either version 2 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License along
+#    with this program; if not, write to the Free Software Foundation, Inc.,
+#    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+import gpt.ad.reverse.foundation.matrix.exp
diff --git a/lib/gpt/ad/reverse/foundation/matrix/exp.py b/lib/gpt/ad/reverse/foundation/matrix/exp.py
new file mode 100644
index 00000000..f75100cb
--- /dev/null
+++ b/lib/gpt/ad/reverse/foundation/matrix/exp.py
@@ -0,0 +1,43 @@
+#
+#    GPT - Grid Python Toolkit
+#    Copyright (C) 2023  Christoph Lehner (christoph.lehner@ur.de, https://github.com/lehner/gpt)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation; either version 2 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License along
+#    with this program; if not, write to the Free Software Foundation, Inc.,
+#    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+import gpt as g
+import numpy as np
+
+
+def function(x):
+    fac = 1.0
+    base = 128.0
+    nbase = 7
+    x = x / base
+    c = x
+    r = g.identity(x)
+    for i in range(1, 10):
+        fac /= float(i)
+        r = r + fac * c
+        c = c * x
+    for i in range(nbase):
+        r = r * r
+    return r
+
+
+# gives 1e-14 / 1e-15 errors up to at least |x| < 10
+
+
+def function_and_gradient(x, dx):
+    assert False