From 39e04d971229f3ca0d1e080d55bf7ac2f7894562 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20Jos=C3=A9=20Pereira?= <patrickelectric@gmail.com>
Date: Mon, 19 Jun 2023 09:35:48 -0300
Subject: [PATCH] lib: matrix: SquareMatrix: Deal with the special case of M=1
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Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>
---
 src/lib/matrix/matrix/SquareMatrix.hpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/lib/matrix/matrix/SquareMatrix.hpp b/src/lib/matrix/matrix/SquareMatrix.hpp
index 20ecd67f2c..4a1d3d0a81 100644
--- a/src/lib/matrix/matrix/SquareMatrix.hpp
+++ b/src/lib/matrix/matrix/SquareMatrix.hpp
@@ -322,6 +322,19 @@ SquareMatrix<Type, M> expm(const Matrix<Type, M, M> &A, size_t order = 5)
 	return res;
 }
 
+/**
+ * Deal with the special case where the square matrix is 1
+ */
+template<typename Type>
+bool inv(const SquareMatrix<Type, 1> &A, SquareMatrix<Type, 1> &inv, size_t rank = 1)
+{
+	if (std::fabs(A(0, 0)) < Type(FLT_EPSILON)) {
+		return false;
+	}
+
+	inv(0, 0) = Type(1) / A(0, 0);
+	return true;
+}
 
 /**
  * inverse based on LU factorization with partial pivotting