---
name: "slasq6"
section: "3lapack"
platform: "linux"
package: "liblapack-doc"
version: "3.2.1-8"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/slasq6/3lapack"
---

# slasq6(3lapack)

computes one dqd (shift equal to zero) transform in ping-pong form, with protection against underflow and overflow

## NAME

SLASQ6 - computes one dqd (shift equal to zero) transform in ping-pong form, with protection against underflow and overflow

## SYNOPSIS

- SUBROUTINE SLASQ6(

  I0, N0, Z, PP, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2 )

- INTEGER

  I0, N0, PP

- REAL

  DMIN, DMIN1, DMIN2, DN, DNM1, DNM2

- REAL

  Z( \* )

## PURPOSE

SLASQ6 computes one dqd (shift equal to zero) transform in ping-pong form, with protection against underflow and overflow.

## ARGUMENTS

- I0 (input) INTEGER

  First index.

- N0 (input) INTEGER

  Last index.

- Z (input) REAL array, dimension ( 4\*N )

  Z holds the qd array. EMIN is stored in Z(4\*N0) to avoid an extra argument.

- PP (input) INTEGER

  PP=0 for ping, PP=1 for pong.

- DMIN (output) REAL

  Minimum value of d. DMIN1 (output) REAL Minimum value of d, excluding D( N0 ). DMIN2 (output) REAL Minimum value of d, excluding D( N0 ) and D( N0-1 ).

- DN (output) REAL

  d(N0), the last value of d.

- DNM1 (output) REAL

  d(N0-1).

- DNM2 (output) REAL

  d(N0-2).