[examples] Add Eigen matrix example

Author: salkinium

examples/nucleo_g474re/eigen/main.cpp

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2025, Henrik Hose
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <modm/board.hpp>
+#include <Eigen/Eigen>
+
+using namespace Board;
+
+Eigen::IOFormat squarebrackets(5, 0, ", ", "\n", "[", "]");
+
+int
+main()
+{
+	Board::initialize();
+	LedD13::setOutput();
+
+	while (1)
+	{
+		Eigen::Matrix2f mat{{1.111f, 2.2222f}, {3.333f, 4.4f}};
+		Eigen::Vector2f u{-1.1f, 1.5f}, v{2.2f, 0.5f};
+		MODM_LOG_INFO.width(2);
+		MODM_LOG_INFO.precision(0);
+		MODM_LOG_INFO << "Here is mat*mat:\n" << mat * mat << modm::endl;
+		MODM_LOG_INFO.width(5);
+		MODM_LOG_INFO.precision(1);
+		MODM_LOG_INFO << "Here is mat*u:\n" << mat * u << modm::endl;
+		MODM_LOG_INFO.width(8);
+		MODM_LOG_INFO.precision(3);
+		MODM_LOG_INFO << "Here is u^T*mat:\n" << u.transpose() * mat << modm::endl;
+		MODM_LOG_INFO.width(10);
+		MODM_LOG_INFO.precision(5);
+		MODM_LOG_INFO << "Here is u^T*v:\n" << u.transpose() * v << modm::endl;
+		MODM_LOG_INFO.width(15);
+		MODM_LOG_INFO.precision(7);
+		MODM_LOG_INFO << "Here is u*v^T:\n" << u * v.transpose() << modm::endl;
+		MODM_LOG_INFO << "Let's multiply mat by itself" << modm::endl;
+		mat = mat * mat;
+		MODM_LOG_INFO << "Now mat is mat:\n" << mat.format(squarebrackets) << modm::endl;
+
+		modm::delay(1s);
+	}
+
+	return 0;
+}

examples/nucleo_g474re/eigen/project.xml

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+<library>
+  <extends>modm:nucleo-g474re</extends>
+  <options>
+    <option name="modm:build:build.path">../../../build/nucleo_g474re/eigen</option>
+  </options>
+  <modules>
+    <module>modm:build:scons</module>
+    <module>modm:platform:heap</module>
+    <module>modm:eigen</module>
+  </modules>
+</library>