From 067b51f18ec4eaabce46d6723c18352df615fff4 Mon Sep 17 00:00:00 2001
From: Ben Reifler <ben.reifler@gmail.com>
Date: Thu, 11 Jul 2024 22:18:28 -0600
Subject: [PATCH] Makes it easier to call `cross`.

---
 PAZ_Math      |  2 +-
 matrix.cpp    | 11 +++++++++++
 test/test.cpp |  2 +-
 vector.cpp    | 11 -----------
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/PAZ_Math b/PAZ_Math
index 2b4d5f3..3720dc9 100644
--- a/PAZ_Math
+++ b/PAZ_Math
@@ -195,6 +195,7 @@ namespace paz
         Mat operator/(double rhs) const;
         Mat operator-() const;
         double dot(const MatRef& rhs) const;
+        Vec cross(const Vec& rhs) const;
         MatRef block(std::size_t startRow, std::size_t startCol, std::size_t
             numRows, std::size_t numCols) const;
         void setBlock(std::size_t startRow, std::size_t startCol, std::size_t
@@ -237,7 +238,6 @@ namespace paz
         MatRef tail(std::size_t n) const;
         void setTail(std::size_t n, const Vec& rhs);
         void resize(std::size_t newRows);
-        Vec cross(const Vec& rhs) const;
     };
 
     class MatRef
diff --git a/matrix.cpp b/matrix.cpp
index d878042..a6b02e1 100644
--- a/matrix.cpp
+++ b/matrix.cpp
@@ -686,6 +686,17 @@ double paz::Mat::dot(const MatRef& rhs) const
     return res;
 }
 
+paz::Vec paz::Mat::cross(const Vec& rhs) const
+{
+    if(rows() != 3 || cols() != 1 || rhs.rows() != 3 || rhs.cols() != 1)
+    {
+        throw std::runtime_error("Not a 3-vector.");
+    }
+    return {{operator()(1)*rhs(2) - operator()(2)*rhs(1),
+             operator()(2)*rhs(0) - operator()(0)*rhs(2),
+             operator()(0)*rhs(1) - operator()(1)*rhs(0)}};
+}
+
 paz::Mat paz::Mat::operator-(const MatRef& rhs) const
 {
     auto res = *this;
diff --git a/test/test.cpp b/test/test.cpp
index 7c76419..d7ea01d 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -75,7 +75,7 @@ int main()
     z.setHead(2, z.tail(2));
     PRINT(z)
 
-    PRINT(static_cast<paz::Vec>(m.row(0).trans()).cross(m.row(1).trans()))
+    PRINT(m.row(0).trans().cross(m.row(1).trans()))
     PRINT(paz::Mat::Cross(m.row(0).trans())*m.row(1).trans())
 
     const paz::Mat x = paz::Mat::Cross(m.row(0).trans())*m.row(1).trans();
diff --git a/vector.cpp b/vector.cpp
index 1b6b955..0f435ab 100644
--- a/vector.cpp
+++ b/vector.cpp
@@ -110,14 +110,3 @@ void paz::Vec::resize(std::size_t newRows)
 {
     resizeRows(newRows);
 }
-
-paz::Vec paz::Vec::cross(const Vec& rhs) const
-{
-    if(size() != 3 || rhs.size() != 3)
-    {
-        throw std::runtime_error("Not a 3-vector.");
-    }
-    return {{(*this)(1)*rhs(2) - (*this)(2)*rhs(1),
-             (*this)(2)*rhs(0) - (*this)(0)*rhs(2),
-             (*this)(0)*rhs(1) - (*this)(1)*rhs(0)}};
-}