From 330f4d289df9232984b59f97245eda9d629b0610 Mon Sep 17 00:00:00 2001
From: Micke Nordin <hej@mic.ke>
Date: Sat, 16 Jul 2022 17:30:59 +0200
Subject: [PATCH] Now with matrix multiplication

---
 matrix.cpp | 40 +++++++++++++++++++++++++++-------------
 matrix.hpp | 32 +++++++++++++++++++++++++++++---
 2 files changed, 56 insertions(+), 16 deletions(-)

diff --git a/matrix.cpp b/matrix.cpp
index 279f52a..87eb15b 100644
--- a/matrix.cpp
+++ b/matrix.cpp
@@ -3,34 +3,48 @@
 #include "../vectors/vector.hpp"
 
 int main() {
-  vector a = vector(3);
+  vector a = vector(2);
   a[0] = cnumber(7, 0);
-  a[1] = cnumber(5, 0);
-  a[2] = cnumber(0, 1);
+  a[1] = cnumber(6, 0);
 
-  vector b = vector(3);
-  b[0] = cnumber(0, 0);
-  b[1] = cnumber(2, 0);
-  b[2] = cnumber(0, 0);
+  vector b = vector(2);
+  b[0] = cnumber(5, 0);
+  b[1] = cnumber(3, 0);
 
-  vector c = vector(3);
-  c[0] = cnumber(0, -1);
-  c[1] = cnumber(0, 0);
-  c[2] = cnumber(4, 0);
+  vector c = vector(2);
+  c[0] = cnumber(2, 0);
+  c[1] = cnumber(5, 0);
 
-  matrix m = matrix(3, 3);
+
+  vector d = vector(2);
+  d[0] = cnumber(1, 0);
+  d[1] = cnumber(0, 1);
+
+  matrix m = matrix(2, 2);
   m[0] = a;
   m[1] = b;
-  m[2] = c;
+
+  matrix n = matrix(2, 2);
+  n[0] = c;
+  n[1] = d;
 
   cout << "The matrix m:" << endl;
   cout << m << endl;
   cout << "The matrix m's transpose:" << endl;
   cout << m.transpose() << endl;
+  cout << "The matrix n" << endl;
+  cout << n << endl;
+  cout << "The matrix m * n" << endl;
+  cout << m * n << endl;
   if  (!m.is_hermitian()) {
     cout << "The matrix m is not hermitian, here is the hermitian conjugate:"
          << endl;
     cout << m.hermitian_conjugate() << endl;
   }
+  if  (!n.is_hermitian()) {
+    cout << "The matrix n is not hermitian, here is the hermitian conjugate:"
+         << endl;
+    cout << n.hermitian_conjugate() << endl;
+  }
   return 0;
 }
diff --git a/matrix.hpp b/matrix.hpp
index cc4ea15..659ee1c 100644
--- a/matrix.hpp
+++ b/matrix.hpp
@@ -21,8 +21,8 @@ public:
   ~matrix() {
     this->num_cols = 0;
     this->num_rows = 0;
-    free(this->cols);
-    this->cols = NULL;
+    //    free(this->cols);
+    // this->cols = NULL;
   }
   const vector get_diagonal() const {
     long long diag_len = this->num_rows;
@@ -39,6 +39,20 @@ public:
     }
     return v;
   }
+  const vector get_row(long long index) const { return this->cols[index]; }
+
+  const vector get_column(long long index) const {
+    vector v(this->num_rows);
+    for (long long j = 0; j < this->num_rows; j++) {
+      v[j] = this->cols[j][index];
+    }
+    return v;
+  }
+
+  const matrix rotate_ninety() const {
+    matrix m(this->num_cols, this->num_rows);
+    return m;
+  }
   const matrix transpose() const {
     matrix n(this->num_rows, this->num_cols);
     for (long long i = 0; i < this->num_cols; i++) {
@@ -64,7 +78,7 @@ public:
   }
   const bool is_hermitian() const {
     if (this->num_rows != this->num_cols)
-	    return false;
+      return false;
     matrix m = this->hermitian_conjugate();
     bool equal = true;
     for (long long i = 0; i < m.num_cols; i++) {
@@ -122,6 +136,18 @@ public:
 
     return n;
   }
+  const matrix operator*(const matrix m) const {
+    matrix n(this->num_cols, m.num_rows);
+    // if (this->num_cols != m.num_rows && m.num_cols != this->num_rows)
+    //   return n;
+    for (long long i = 0; i < this->num_rows; i++) {
+      for (long long j = 0; j < this->num_rows; j++) {
+        n[i][j] = this->get_row(i) * m.get_column(j);
+      }
+    }
+
+    return n;
+  }
 
   const matrix operator+(const matrix &m) const {
     matrix n(this->num_cols, this->num_rows);