LAPACK  3.10.0 LAPACK: Linear Algebra PACKage

## ◆ dzsum1()

 double precision function dzsum1 ( integer N, complex*16, dimension( * ) CX, integer INCX )

DZSUM1 forms the 1-norm of the complex vector using the true absolute value.

Purpose:
``` DZSUM1 takes the sum of the absolute values of a complex
vector and returns a double precision result.

Based on DZASUM from the Level 1 BLAS.
The change is to use the 'genuine' absolute value.```
Parameters
 [in] N ``` N is INTEGER The number of elements in the vector CX.``` [in] CX ``` CX is COMPLEX*16 array, dimension (N) The vector whose elements will be summed.``` [in] INCX ``` INCX is INTEGER The spacing between successive values of CX. INCX > 0.```
Contributors:
Nick Higham for use with ZLACON.

Definition at line 80 of file dzsum1.f.

81 *
82 * -- LAPACK auxiliary routine --
83 * -- LAPACK is a software package provided by Univ. of Tennessee, --
84 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
85 *
86 * .. Scalar Arguments ..
87  INTEGER INCX, N
88 * ..
89 * .. Array Arguments ..
90  COMPLEX*16 CX( * )
91 * ..
92 *
93 * =====================================================================
94 *
95 * .. Local Scalars ..
96  INTEGER I, NINCX
97  DOUBLE PRECISION STEMP
98 * ..
99 * .. Intrinsic Functions ..
100  INTRINSIC abs
101 * ..
102 * .. Executable Statements ..
103 *
104  dzsum1 = 0.0d0
105  stemp = 0.0d0
106  IF( n.LE.0 )
107  \$ RETURN
108  IF( incx.EQ.1 )
109  \$ GO TO 20
110 *
111 * CODE FOR INCREMENT NOT EQUAL TO 1
112 *
113  nincx = n*incx
114  DO 10 i = 1, nincx, incx
115 *
116 * NEXT LINE MODIFIED.
117 *
118  stemp = stemp + abs( cx( i ) )
119  10 CONTINUE
120  dzsum1 = stemp
121  RETURN
122 *
123 * CODE FOR INCREMENT EQUAL TO 1
124 *
125  20 CONTINUE
126  DO 30 i = 1, n
127 *
128 * NEXT LINE MODIFIED.
129 *
130  stemp = stemp + abs( cx( i ) )
131  30 CONTINUE
132  dzsum1 = stemp
133  RETURN
134 *
135 * End of DZSUM1
136 *
double precision function dzsum1(N, CX, INCX)
DZSUM1 forms the 1-norm of the complex vector using the true absolute value.
Definition: dzsum1.f:81