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2D and 3D variants of det

This commit is contained in:
Zeno Rogue 2020-08-20 16:11:35 +02:00
parent 58aba3eb37
commit c932ae4399
1 changed files with 17 additions and 8 deletions
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25
hyperpoint.cpp
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@ -879,16 +879,25 @@ EX void orthonormalize(transmatrix& T) {
}
}
/** determinant 2x2 */
EX ld det2(const transmatrix& T) {
return T[0][0] * T[1][1] - T[0][1] * T[1][0];
}
/** determinant 3x3 */
EX ld det3(const transmatrix& T) {
ld det = 0;
for(int i=0; i<3; i++)
det += T[0][i] * T[1][(i+1)%3] * T[2][(i+2)%3];
for(int i=0; i<3; i++)
det -= T[0][i] * T[1][(i+2)%3] * T[2][(i+1)%3];
return det;
}
/** determinant */
EX ld det(const transmatrix& T) {
if(GDIM == 2) {
ld det = 0;
for(int i=0; i<3; i++)
det += T[0][i] * T[1][(i+1)%3] * T[2][(i+2)%3];
for(int i=0; i<3; i++)
det -= T[0][i] * T[1][(i+2)%3] * T[2][(i+1)%3];
return det;
}
if(GDIM == 2)
retrun det3(T);
else {
ld det = 1;
transmatrix M = T;