# dlabad.f man page

dlabad.f

## Synopsis

### Functions/Subroutines

subroutine **dlabad** (SMALL, LARGE)**DLABAD**

## Function/Subroutine Documentation

### subroutine dlabad (double precision SMALL, double precision LARGE)

**DLABAD**

**Purpose:**

DLABAD takes as input the values computed by DLAMCH for underflow and overflow, and returns the square root of each of these values if the log of LARGE is sufficiently large. This subroutine is intended to identify machines with a large exponent range, such as the Crays, and redefine the underflow and overflow limits to be the square roots of the values computed by DLAMCH. This subroutine is needed because DLAMCH does not compensate for poor arithmetic in the upper half of the exponent range, as is found on a Cray.

**Parameters:***SMALL*SMALL is DOUBLE PRECISION On entry, the underflow threshold as computed by DLAMCH. On exit, if LOG10(LARGE) is sufficiently large, the square root of SMALL, otherwise unchanged.

*LARGE*LARGE is DOUBLE PRECISION On entry, the overflow threshold as computed by DLAMCH. On exit, if LOG10(LARGE) is sufficiently large, the square root of LARGE, otherwise unchanged.

**Author:**Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**December 2016

Definition at line 76 of file dlabad.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dlabad(3) is an alias of dlabad.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK