Tensor tutorial: Operators and Modification

doc/indices.md

+# Indices and Equations
+
+## Blockwise Construction of Tensors
+

include/xerus/tensor.h

@@ -737,11 +737,11 @@ namespace xerus {
 		
 		
 		/** 
-		 * @brief Performs the trace over the given indices
-		 * @param _firstIndex the first index involved in the trace.
-		 * @param _secondIndex the second index involved in the trace.
+		 * @brief Performs the trace over the given modes
+		 * @param _firstMode the first mode involved in the trace.
+		 * @param _secondMode the second mode involved in the trace.
 		 */
-		void perform_trace(size_t _firstIndex, size_t _secondIndex);
+		void perform_trace(size_t _firstMode, size_t _secondMode);
 		
 		
 		/** 

src/xerus/python/python.cpp

@@ -463,12 +463,35 @@ BOOST_PYTHON_MODULE(xerus) {
 			.def("sparsity", &Tensor::sparsity)
 			.def("all_entries_valid", &Tensor::all_entries_valid)
 			.def("reorder_cost", &Tensor::reorder_cost)
-			.def("reinterpret_dimensions", &Tensor::reinterpret_dimensions)
+			.def("reinterpret_dimensions", &Tensor::reinterpret_dimensions,
+				arg("dim"),
+				"Reinterprets the dimensions of the tensor."
+				parametersDocstr
+				"dim : list or tuple of int"
+			)
 			.def("resize_mode", &Tensor::resize_mode,
-				(arg("mode"), arg("newDimension"), arg("cutPosition")=~0ul)
+				(arg("mode"), arg("newDim"), arg("cutPos")=~0ul),
+				"Resizes a specific mode of the Tensor."
+				parametersDocstr
+				"mode : int\n"
+				"newDim : int\n"
+				"cutPos : int, optional (default: infinity)\n"
+				"    The position within the selected mode in front of which slates are inserted or removed."
+			)
+			.def("fix_mode", &Tensor::fix_mode,
+				(arg("mode"), arg("value")),
+				"Fixes a specific mode to a specific value, effectively reducing the order by one."
+				parametersDocstr
+				"mode : int\n"
+				"value : int"
+			)
+			.def("remove_slate", &Tensor::remove_slate,
+				((arg("mode"), arg("pos")),
+				"Removes a single slate from the Tensor, reducing dimension[mode] by one."
+				parametersDocstr
+				"mode : int\n"
+				"pos : int"
 			)
-			.def("fix_mode", &Tensor::fix_mode)
-			.def("remove_slate", &Tensor::remove_slate)
 			.def("perform_trace", &Tensor::perform_trace)
 			.def("offset_add", &Tensor::offset_add)
 			.def("use_dense_representation", &Tensor::use_dense_representation)

src/xerus/tensor.cpp

@@ -768,18 +768,18 @@ namespace xerus {
 	}
 	
 	
-	void Tensor::perform_trace(size_t _firstIndex, size_t _secondIndex) {
-		REQUIRE(_firstIndex != _secondIndex, "Given indices must not coincide");
-		REQUIRE(dimensions[_firstIndex] == dimensions[_secondIndex], "Dimensions of trace indices must coincide.");
+	void Tensor::perform_trace(size_t _firstMode, size_t _secondMode) {
+		REQUIRE(_firstMode != _secondMode, "Given indices must not coincide");
+		REQUIRE(dimensions[_firstMode] == dimensions[_secondMode], "Dimensions of trace indices must coincide.");
 		
-		if(_firstIndex > _secondIndex) { std::swap(_firstIndex, _secondIndex); }
+		if(_firstMode > _secondMode) { std::swap(_firstMode, _secondMode); }
 		
 		
 		
-		const size_t front = misc::product(dimensions, 0, _firstIndex);
-		const size_t mid = misc::product(dimensions, _firstIndex+1, _secondIndex);
-		const size_t back = misc::product(dimensions, _secondIndex+1, degree());
-		const size_t traceDim = dimensions[_firstIndex];
+		const size_t front = misc::product(dimensions, 0, _firstMode);
+		const size_t mid = misc::product(dimensions, _firstMode+1, _secondMode);
+		const size_t back = misc::product(dimensions, _secondMode+1, degree());
+		const size_t traceDim = dimensions[_firstMode];
 		const size_t frontStepSize = traceDim*mid*traceDim*back;
 		const size_t traceStepSize = mid*traceDim*back+back;
 		const size_t midStepSize = traceDim*back;
@@ -822,8 +822,8 @@ namespace xerus {
 			sparseData.reset(newData.release());
 		}
 		
-		dimensions.erase(dimensions.begin()+_secondIndex);
-		dimensions.erase(dimensions.begin()+_firstIndex);
+		dimensions.erase(dimensions.begin()+_secondMode);
+		dimensions.erase(dimensions.begin()+_firstMode);
 		factor = 1.0;
 	}