Create the values for a Givens 2-by-2 rotation matrix.
Create the values for a Givens 2-by-2 rotation matrix. Given scalars 'y' and 'z', efficiently compute 'c = cos(theta)' and 's = sin(theta)' that can be used to form the rotation matrix.
the first scalar
the second scalar
Algorithm 5.1.3 in Matrix Computation.
Efficiently perform a Givens column update: a = a * g (i, k, theta).
Efficiently perform a Givens column update: a = a * g (i, k, theta). The update just affects two columns. FIX
the matrix to update
the first column ??
the second column ??
the (cosine, sine) of theta
Return a Givens rotation matrix with angle 'theta = atan(s/c)'.
Return a Givens rotation matrix with angle 'theta = atan(s/c)'. A matrix is post-multiplied by the Given matrix to clear element (i, k). The 2-by-2 rotation is embedded in an identity matrix of dimension 'n'.
the first diagonal position (i, i)
the second diagonal position (k, k)
the dimension of the resulting rotation matrix
the (cosine, sine) of theta
Return a transposed Givens rotation matrix with angle 'theta = atan(s/c)'.
Return a transposed Givens rotation matrix with angle 'theta = atan(s/c)'. A matrix is pre-multiplied by the Given matrix to clear element (k, i). The 2-by-2 rotation is embedded in an identity matrix of dimension 'n'.
the first diagonal position (i, i)
the second diagonal position (k, k)
the dimension of the resulting rotation matrix
the (cosine, sine) of theta
Efficiently perform a Givens row update: 'a = g (i, k, theta).
Efficiently perform a Givens row update: 'a = g (i, k, theta).t * a'. The update just affects two row. FIX
the matrix to update
the first row ??
the second row ??
the (cosine, sine) of theta
The
Givens
objects has methods for determinng values 'c = cos(theta)' and 's = sin(theta) for Givens rotation matrices as well as methods for applying Givens rotations.