| 135 |
|
|
| 136 |
|
return tmp; |
| 137 |
|
} |
| 138 |
+ |
|
| 139 |
+ |
/** |
| 140 |
+ |
* Returns the tensor contraction (double dot product) of two rank 2 |
| 141 |
+ |
* tensors (or Matrices) |
| 142 |
+ |
* @param t1 first tensor |
| 143 |
+ |
* @param t2 second tensor |
| 144 |
+ |
* @return the tensor contraction (double dot product) of t1 and t2 |
| 145 |
+ |
*/ |
| 146 |
+ |
Real doubleDot( const SquareMatrix<Real, Dim>& t1, const SquareMatrix<Real, Dim>& t2 ) { |
| 147 |
+ |
Real tmp; |
| 148 |
+ |
tmp = 0; |
| 149 |
+ |
|
| 150 |
+ |
for (unsigned int i = 0; i < Dim; i++) |
| 151 |
+ |
for (unsigned int j =0; j < Dim; j++) |
| 152 |
+ |
tmp += t1[i][j] * t2[i][j]; |
| 153 |
+ |
|
| 154 |
+ |
return tmp; |
| 155 |
+ |
} |
| 156 |
|
|
| 157 |
|
/** Tests if this matrix is symmetrix. */ |
| 158 |
|
bool isSymmetric() const { |
| 183 |
|
return true; |
| 184 |
|
} |
| 185 |
|
|
| 186 |
+ |
/** |
| 187 |
+ |
* Returns a column vector that contains the elements from the |
| 188 |
+ |
* diagonal of m in the order R(0) = m(0,0), R(1) = m(1,1), and so |
| 189 |
+ |
* on. |
| 190 |
+ |
*/ |
| 191 |
+ |
Vector<Real, Dim> diagonals() const { |
| 192 |
+ |
Vector<Real, Dim> result; |
| 193 |
+ |
for (unsigned int i = 0; i < Dim; i++) { |
| 194 |
+ |
result(i) = this->data_[i][i]; |
| 195 |
+ |
} |
| 196 |
+ |
return result; |
| 197 |
+ |
} |
| 198 |
+ |
|
| 199 |
|
/** Tests if this matrix is the unit matrix. */ |
| 200 |
|
bool isUnitMatrix() const { |
| 201 |
|
if (!isDiagonal()) |
