slae2.f(3) [debian man page]
slae2.f(3) LAPACK slae2.f(3) NAME
slae2.f - SYNOPSIS
Functions/Subroutines subroutine slae2 (A, B, C, RT1, RT2) SLAE2 Function/Subroutine Documentation subroutine slae2 (realA, realB, realC, realRT1, realRT2) SLAE2 Purpose: SLAE2 computes the eigenvalues of a 2-by-2 symmetric matrix [ A B ] [ B C ]. On return, RT1 is the eigenvalue of larger absolute value, and RT2 is the eigenvalue of smaller absolute value. Parameters: A A is REAL The (1,1) element of the 2-by-2 matrix. B B is REAL The (1,2) and (2,1) elements of the 2-by-2 matrix. C C is REAL The (2,2) element of the 2-by-2 matrix. RT1 RT1 is REAL The eigenvalue of larger absolute value. RT2 RT2 is REAL The eigenvalue of smaller absolute value. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: November 2011 Further Details: RT1 is accurate to a few ulps barring over/underflow. RT2 may be inaccurate if there is massive cancellation in the determinant A*C-B*B; higher precision or correctly rounded or correctly truncated arithmetic would be needed to compute RT2 accurately in all cases. Overflow is possible only if RT1 is within a factor of 5 of overflow. Underflow is harmless if the input data is 0 or exceeds underflow_threshold / macheps. Definition at line 103 of file slae2.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.1 Sun May 26 2013 slae2.f(3)
Check Out this Related Man Page
slae2.f(3) LAPACK slae2.f(3) NAME
slae2.f - SYNOPSIS
Functions/Subroutines subroutine slae2 (A, B, C, RT1, RT2) SLAE2 Function/Subroutine Documentation subroutine slae2 (realA, realB, realC, realRT1, realRT2) SLAE2 Purpose: SLAE2 computes the eigenvalues of a 2-by-2 symmetric matrix [ A B ] [ B C ]. On return, RT1 is the eigenvalue of larger absolute value, and RT2 is the eigenvalue of smaller absolute value. Parameters: A A is REAL The (1,1) element of the 2-by-2 matrix. B B is REAL The (1,2) and (2,1) elements of the 2-by-2 matrix. C C is REAL The (2,2) element of the 2-by-2 matrix. RT1 RT1 is REAL The eigenvalue of larger absolute value. RT2 RT2 is REAL The eigenvalue of smaller absolute value. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: November 2011 Further Details: RT1 is accurate to a few ulps barring over/underflow. RT2 may be inaccurate if there is massive cancellation in the determinant A*C-B*B; higher precision or correctly rounded or correctly truncated arithmetic would be needed to compute RT2 accurately in all cases. Overflow is possible only if RT1 is within a factor of 5 of overflow. Underflow is harmless if the input data is 0 or exceeds underflow_threshold / macheps. Definition at line 103 of file slae2.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.1 Sun May 26 2013 slae2.f(3)