---
name: "dsxt1.f"
section: "3"
platform: "linux"
package: "lapack-doc"
version: "3.12.1-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/dsxt1.f"
---

# dsxt1.f(3)

## NAME

TESTING/EIG/dsxt1.f

## SYNOPSIS

### Functions/Subroutines

double precision function **dsxt1** (ijob, d1, n1, d2, n2, abstol, ulp, unfl)\
 **DSXT1**

## Function/Subroutine Documentation

### double precision function dsxt1 (integer ijob, double precision, dimension( \* ) d1, integer n1, double precision, dimension( \* ) d2, integer n2, double precision abstol, double precision ulp, double precision unfl)

**DSXT1**

**Purpose:**

```
!>
!> DSXT1  computes the difference between a set of eigenvalues.
!> The result is returned as the function value.
!>
!> IJOB = 1:   Computes   max { min | D1(i)-D2(j) | }
!>                         i     j
!>
!> IJOB = 2:   Computes   max { min | D1(i)-D2(j) | /
!>                         i     j
!>                              ( ABSTOL + |D1(i)|*ULP ) }
!>
```

**Parameters**

*IJOB*

```
!>          IJOB is INTEGER
!>          Specifies the type of tests to be performed.  (See above.)
!>
```

*D1*

```
!>          D1 is DOUBLE PRECISION array, dimension (N1)
!>          The first array.  D1 should be in increasing order, i.e.,
!>          D1(j) <= D1(j+1).
!>
```

*N1*

```
!>          N1 is INTEGER
!>          The length of D1.
!>
```

*D2*

```
!>          D2 is DOUBLE PRECISION array, dimension (N2)
!>          The second array.  D2 should be in increasing order, i.e.,
!>          D2(j) <= D2(j+1).
!>
```

*N2*

```
!>          N2 is INTEGER
!>          The length of D2.
!>
```

*ABSTOL*

```
!>          ABSTOL is DOUBLE PRECISION
!>          The absolute tolerance, used as a measure of the error.
!>
```

*ULP*

```
!>          ULP is DOUBLE PRECISION
!>          Machine precision.
!>
```

*UNFL*

```
!>          UNFL is DOUBLE PRECISION
!>          The smallest positive number whose reciprocal does not
!>          overflow.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **104** of file **dsxt1.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.