---
name: "cchkec.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/cchkec.f"
---

# cchkec.f(3)

## NAME

TESTING/EIG/cchkec.f

## SYNOPSIS

### Functions/Subroutines

subroutine **cchkec** (thresh, tsterr, nin, nout)\
 **CCHKEC**

## Function/Subroutine Documentation

### subroutine cchkec (real thresh, logical tsterr, integer nin, integer nout)

**CCHKEC**

**Purpose:**

```
!>
!> CCHKEC tests eigen- condition estimation routines
!>        CTRSYL, CTRSYL3, CTREXC, CTRSNA, CTRSEN
!>
!> In all cases, the routine runs through a fixed set of numerical
!> examples, subjects them to various tests, and compares the test
!> results to a threshold THRESH. In addition, CTRSNA and CTRSEN are
!> tested by reading in precomputed examples from a file (on input unit
!> NIN).  Output is written to output unit NOUT.
!>
```

**Parameters**

*THRESH*

```
!>          THRESH is REAL
!>          Threshold for residual tests.  A computed test ratio passes
!>          the threshold if it is less than THRESH.
!>
```

*TSTERR*

```
!>          TSTERR is LOGICAL
!>          Flag that indicates whether error exits are to be tested.
!>
```

*NIN*

```
!>          NIN is INTEGER
!>          The logical unit number for input.
!>
```

*NOUT*

```
!>          NOUT is INTEGER
!>          The logical unit number for output.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **74** of file **cchkec.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.