Provided by: liblapack-doc_3.3.1-1_all

NAME

```       LAPACK-3  - returns the values scl and ssq such that   ( scl**2 )*ssq = x( 1 )**2 +...+ x(
n )**2 + ( scale**2 )*sumsq,

```

SYNOPSIS

```       SUBROUTINE ZLASSQ( N, X, INCX, SCALE, SUMSQ )

INTEGER        INCX, N

DOUBLE         PRECISION SCALE, SUMSQ

COMPLEX*16     X( * )

```

PURPOSE

```       ZLASSQ returns the values scl and ssq such that
where x( i ) = abs( X( 1 + ( i - 1 )*INCX ) ). The value of sumsq is
assumed to be at least unity and the value of ssq will then satisfy
1.0 .le. ssq .le. ( sumsq + 2*n ).
scale is assumed to be non-negative and scl returns the value
scl = max( scale, abs( real( x( i ) ) ), abs( aimag( x( i ) ) ) ),
i
scale and sumsq must be supplied in SCALE and SUMSQ respectively.
SCALE and SUMSQ are overwritten by scl and ssq respectively.
The routine makes only one pass through the vector X.

```

ARGUMENTS

```        N       (input) INTEGER
The number of elements to be used from the vector X.

X       (input) COMPLEX*16 array, dimension (N)
The vector x as described above.
x( i )  = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n.

INCX    (input) INTEGER
The increment between successive values of the vector X.
INCX > 0.

SCALE   (input/output) DOUBLE PRECISION
On entry, the value  scale  in the equation above.
On exit, SCALE is overwritten with the value  scl .

SUMSQ   (input/output) DOUBLE PRECISION
On entry, the value  sumsq  in the equation above.
On exit, SUMSQ is overwritten with the value  ssq .

LAPACK auxiliary routine (version 3.2)     April 2011                            ZLASSQ(3lapack)
```