ctrdi.f
SUBROUTINE CTRDI (T, LDT, N, DET, JOB, INFO)
C***BEGIN PROLOGUE CTRDI
C***PURPOSE Compute the determinant and inverse of a triangular matrix.
C***LIBRARY SLATEC (LINPACK)
C***CATEGORY D2C3, D3C3
C***TYPE COMPLEX (STRDI-S, DTRDI-D, CTRDI-C)
C***KEYWORDS DETERMINANT, INVERSE, LINEAR ALGEBRA, LINPACK,
C TRIANGULAR MATRIX
C***AUTHOR Moler, C. B., (U. of New Mexico)
C***DESCRIPTION
C
C CTRDI computes the determinant and inverse of a complex
C triangular matrix.
C
C On Entry
C
C T COMPLEX(LDT,N)
C T contains the triangular matrix. The zero
C elements of the matrix are not referenced, and
C the corresponding elements of the array can be
C used to store other information.
C
C LDT INTEGER
C LDT is the leading dimension of the array T.
C
C N INTEGER
C N is the order of the system.
C
C JOB INTEGER
C = 010 no det, inverse of lower triangular.
C = 011 no det, inverse of upper triangular.
C = 100 det, no inverse.
C = 110 det, inverse of lower triangular.
C = 111 det, inverse of upper triangular.
C
C On Return
C
C T inverse of original matrix if requested.
C Otherwise unchanged.
C
C DET COMPLEX(2)
C determinant of original matrix if requested.
C Otherwise not referenced.
C Determinant = DET(1) * 10.0**DET(2)
C with 1.0 .LE. CABS1(DET(1)) .LT. 10.0
C or DET(1) .EQ. 0.0 .
C
C INFO INTEGER
C INFO contains zero if the system is nonsingular
C and the inverse is requested.
C Otherwise INFO contains the index of
C a zero diagonal element of T.
C
C
C***REFERENCES J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
C Stewart, LINPACK Users' Guide, SIAM, 1979.
C***ROUTINES CALLED CAXPY, CSCAL
C***REVISION HISTORY (YYMMDD)
C 780814 DATE WRITTEN
C 890831 Modified array declarations. (WRB)
C 890831 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900326 Removed duplicate information from DESCRIPTION section.
C (WRB)
C 920501 Reformatted the REFERENCES section. (WRB)
C***END PROLOGUE CTRDI