SparseDifferentiation · Transurgeon · Apr 11, 2026 · Apr 11, 2026 · Apr 12, 2026 · Apr 14, 2026
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -4,8 +4,8 @@ set(CMAKE_C_STANDARD 99)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 set(DIFF_ENGINE_VERSION_MAJOR 0)
-set(DIFF_ENGINE_VERSION_MINOR 1)
-set(DIFF_ENGINE_VERSION_PATCH 6)
+set(DIFF_ENGINE_VERSION_MINOR 2)
+set(DIFF_ENGINE_VERSION_PATCH 2)
 set(DIFF_ENGINE_VERSION "${DIFF_ENGINE_VERSION_MAJOR}.${DIFF_ENGINE_VERSION_MINOR}.${DIFF_ENGINE_VERSION_PATCH}")
 add_compile_definitions(DIFF_ENGINE_VERSION="${DIFF_ENGINE_VERSION}")
 

diff --git a/include/atoms/affine.h b/include/atoms/affine.h
@@ -1,7 +1,7 @@
 /*
  * Copyright 2026 Daniel Cederberg and William Zhang
  *
- * This file is part of the DNLP-differentiation-engine project.
+ * This file is part of the SparseDiffEngine project.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +38,8 @@ expr *new_index(expr *child, int d1, int d2, const int *indices, int n_idxs);
 expr *new_reshape(expr *child, int d1, int d2);
 expr *new_broadcast(expr *child, int target_d1, int target_d2);
 expr *new_diag_vec(expr *child);
+expr *new_diag_mat(expr *child);
+expr *new_upper_tri(expr *child);
 expr *new_transpose(expr *child);
 
 /* Left matrix multiplication: A @ f(x) where A is a constant or parameter

diff --git a/include/atoms/bivariate_full_dom.h b/include/atoms/bivariate_full_dom.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef BIVARIATE_FULL_DOM_H
 #define BIVARIATE_FULL_DOM_H
 

diff --git a/include/atoms/bivariate_restricted_dom.h b/include/atoms/bivariate_restricted_dom.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef BIVARIATE_RESTRICTED_DOM_H
 #define BIVARIATE_RESTRICTED_DOM_H
 

diff --git a/include/atoms/elementwise_full_dom.h b/include/atoms/elementwise_full_dom.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef ELEMENTWISE_FULL_DOM_H
 #define ELEMENTWISE_FULL_DOM_H
 

diff --git a/include/atoms/elementwise_restricted_dom.h b/include/atoms/elementwise_restricted_dom.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef ELEMENTWISE_RESTRICTED_DOM_H
 #define ELEMENTWISE_RESTRICTED_DOM_H
 

diff --git a/include/atoms/non_elementwise_full_dom.h b/include/atoms/non_elementwise_full_dom.h
@@ -1,7 +1,7 @@
 /*
  * Copyright 2026 Daniel Cederberg and William Zhang
  *
- * This file is part of the DNLP-differentiation-engine project.
+ * This file is part of the SparseDiffEngine project.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

diff --git a/include/expr.h b/include/expr.h
@@ -1,7 +1,7 @@
 /*
  * Copyright 2026 Daniel Cederberg and William Zhang
  *
- * This file is part of the DNLP-differentiation-engine project.
+ * This file is part of the SparseDiffEngine project.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

diff --git a/include/old-code/old_CSR.h b/include/old-code/old_CSR.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef OLD_CSR_H
 #define OLD_CSR_H
 

diff --git a/include/old-code/old_CSR_sum.h b/include/old-code/old_CSR_sum.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef OLD_CSR_SUM_H
 #define OLD_CSR_SUM_H
 

diff --git a/include/old-code/old_affine.h b/include/old-code/old_affine.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef OLD_AFFINE_H
 #define OLD_AFFINE_H
 

diff --git a/include/problem.h b/include/problem.h
@@ -1,7 +1,7 @@
 /*
  * Copyright 2026 Daniel Cederberg and William Zhang
  *
- * This file is part of the DNLP-differentiation-engine project.
+ * This file is part of the SparseDiffEngine project.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

diff --git a/include/subexpr.h b/include/subexpr.h
@@ -1,7 +1,7 @@
 /*
  * Copyright 2026 Daniel Cederberg and William Zhang
  *
- * This file is part of the DNLP-differentiation-engine project.
+ * This file is part of the SparseDiffEngine project.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

diff --git a/include/utils/COO_Matrix.h b/include/utils/COO_Matrix.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef COO_MATRIX_H
 #define COO_MATRIX_H
 

diff --git a/include/utils/CSC_Matrix.h b/include/utils/CSC_Matrix.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef CSC_MATRIX_H
 #define CSC_MATRIX_H
 

diff --git a/include/utils/CSR_Matrix.h b/include/utils/CSR_Matrix.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef CSR_MATRIX_H
 #define CSR_MATRIX_H
 #include <stdbool.h>

diff --git a/include/utils/CSR_sum.h b/include/utils/CSR_sum.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef CSR_SUM_H
 #define CSR_SUM_H
 

diff --git a/include/utils/Timer.h b/include/utils/Timer.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 /*
  * Copyright 2025 Daniel Cederberg
  *

diff --git a/include/utils/Vec_macros.h b/include/utils/Vec_macros.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 /*
  * Copyright 2025 Daniel Cederberg
  *

diff --git a/include/utils/cblas_wrapper.h b/include/utils/cblas_wrapper.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef CBLAS_WRAPPER_H
 #define CBLAS_WRAPPER_H
 

diff --git a/include/utils/dense_matrix.h b/include/utils/dense_matrix.h
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2026 Daniel Cederberg and William Zhang
+ *
+ * This file is part of the SparseDiffEngine project.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 #ifndef DENSE_MATRIX_H
 #define DENSE_MATRIX_H