LAPACK 3.11.0 LAPACK: Linear Algebra PACKage
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## ◆ icmax1()

 integer function icmax1 ( integer N, complex, dimension(*) CX, integer INCX )

ICMAX1 finds the index of the first vector element of maximum absolute value.

Download ICMAX1 + dependencies [TGZ] [ZIP] [TXT]

Purpose:
``` ICMAX1 finds the index of the first vector element of maximum absolute value.

Based on ICAMAX from 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 array, dimension (N) The vector CX. The ICMAX1 function returns the index of its first element of maximum absolute value.``` [in] INCX ``` INCX is INTEGER The spacing between successive values of CX. INCX >= 1.```
Contributors:
Nick Higham for use with CLACON.

Definition at line 80 of file icmax1.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 CX(*)
91* ..
92*
93* =====================================================================
94*
95* .. Local Scalars ..
96 REAL SMAX
97 INTEGER I, IX
98* ..
99* .. Intrinsic Functions ..
100 INTRINSIC abs
101* ..
102* .. Executable Statements ..
103*
104 icmax1 = 0
105 IF (n.LT.1 .OR. incx.LE.0) RETURN
106 icmax1 = 1
107 IF (n.EQ.1) RETURN
108 IF (incx.EQ.1) THEN
109*
110* code for increment equal to 1
111*
112 smax = abs(cx(1))
113 DO i = 2,n
114 IF (abs(cx(i)).GT.smax) THEN
115 icmax1 = i
116 smax = abs(cx(i))
117 END IF
118 END DO
119 ELSE
120*
121* code for increment not equal to 1
122*
123 ix = 1
124 smax = abs(cx(1))
125 ix = ix + incx
126 DO i = 2,n
127 IF (abs(cx(ix)).GT.smax) THEN
128 icmax1 = i
129 smax = abs(cx(ix))
130 END IF
131 ix = ix + incx
132 END DO
133 END IF
134 RETURN
135*
136* End of ICMAX1
137*
integer function icmax1(N, CX, INCX)
ICMAX1 finds the index of the first vector element of maximum absolute value.
Definition: icmax1.f:81
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