remove unnecessary duplicate matrices from inverse

This commit is contained in:
Siddharth Bharat Purohit 2017-02-03 23:50:09 +05:30 committed by James Goppert
parent 47c0a93140
commit 7e3eff7b2d

View File

@ -47,9 +47,23 @@ public:
// inverse alias
inline SquareMatrix<Type, M> I() const
{
return inv(*this);
SquareMatrix<Type, M> i;
if(inv(*this, i)) {
return i;
} else {
i.setZero();
return i;
}
}
// inverse alias
inline bool I(SquareMatrix<Type, M> &i) const
{
return inv(*this, i);
}
Vector<Type, M> diag() const
{
Vector<Type, M> res;
@ -108,11 +122,12 @@ SquareMatrix<Type, M> expm(const Matrix<Type, M, M> & A, size_t order=5)
return res;
}
/**
* inverse based on LU factorization with partial pivotting
*/
template<typename Type, size_t M>
SquareMatrix <Type, M> inv(const SquareMatrix<Type, M> & A)
bool inv(const SquareMatrix<Type, M> & A, SquareMatrix<Type, M> & inv)
{
SquareMatrix<Type, M> L;
L.setIdentity();
@ -147,14 +162,12 @@ SquareMatrix <Type, M> inv(const SquareMatrix<Type, M> & A)
//printf("U:\n"); U.print();
//printf("P:\n"); P.print();
//fflush(stdout);
ASSERT(fabsf(U(n, n)) > 1e-8f);
//ASSERT(fabsf(U(n, n)) > 1e-8f);
#endif
// failsafe, return zero matrix
if (fabsf(U(n, n)) < 1e-8f) {
SquareMatrix<Type, M> zero;
zero.setZero();
return zero;
return false;
}
// for all rows below diagonal
@ -173,7 +186,7 @@ SquareMatrix <Type, M> inv(const SquareMatrix<Type, M> & A)
//printf("U:\n"); U.print();
// solve LY=P*I for Y by forward subst
SquareMatrix<Type, M> Y = P;
//SquareMatrix<Type, M> Y = P;
// for all columns of Y
for (size_t c = 0; c < M; c++) {
@ -184,7 +197,7 @@ SquareMatrix <Type, M> inv(const SquareMatrix<Type, M> & A)
// for all existing y
// subtract the component they
// contribute to the solution
Y(i, c) -= L(i, j) * Y(j, c);
P(i, c) -= L(i, j) * P(j, c);
}
// divide by the factor
@ -198,7 +211,7 @@ SquareMatrix <Type, M> inv(const SquareMatrix<Type, M> & A)
//printf("Y:\n"); Y.print();
// solve Ux=y for x by back subst
SquareMatrix<Type, M> X = Y;
//SquareMatrix<Type, M> X = Y;
// for all columns of X
for (size_t c = 0; c < M; c++) {
@ -212,20 +225,46 @@ SquareMatrix <Type, M> inv(const SquareMatrix<Type, M> & A)
// for all existing x
// subtract the component they
// contribute to the solution
X(i, c) -= U(i, j) * X(j, c);
P(i, c) -= U(i, j) * P(j, c);
}
// divide by the factor
// on current
// term to be solved
X(i, c) /= U(i, i);
if(fabsf(U(i,i)) < 1e-8f) {
return false;
}
P(i, c) /= U(i, i);
}
}
//check sanity of results
for (uint8_t i = 0; i < M; i++) {
for (uint8_t j = 0; j < M; j++) {
if (!PX4_ISFINITE(P(i,j))) {
return false;
}
}
}
//printf("X:\n"); X.print();
return X;
inv = P;
return true;
}
/**
* inverse based on LU factorization with partial pivotting
*/
template<typename Type, size_t M>
SquareMatrix<Type, M> inv(const SquareMatrix<Type, M> & A)
{
SquareMatrix<Type, M> i;
if(inv(A, i)) {
return i;
} else {
i.setZero();
return i;
}
}
typedef SquareMatrix<float, 3> Matrix3f;
} // namespace matrix