Routines (alphabetical) > Routines: C > CONJ

# CONJ

The CONJ function returns the complex conjugate of X. The complex conjugate of the real-imaginary pair (x, y) is (x, -y). If X is not complex, a complex-valued copy of X is used.

## Examples

Print the conjugate of the complex pair (4.0, 5.0) by entering:

PRINT, CONJ(COMPLEX(4.0, 5.0))

IDL prints:

( 4.00000, -5.00000)

## Syntax

Result = CONJ(X)

## Return Value

Returns the complex conjugate of X.

## Arguments

### X

The value for which the complex conjugate is desired. If X is an array, the result has the same structure, with each element containing the complex conjugate of the corresponding element of X.

## Keywords

### Thread Pool Keywords

This routine is written to make use of IDL’s thread pool, which can increase execution speed on systems with multiple CPUs. The values stored in the !CPU system variable control whether IDL uses the thread pool for a given computation. In addition, you can use the thread pool keywords TPOOL_MAX_ELTS, TPOOL_MIN_ELTS, and TPOOL_NOTHREAD to override the defaults established by !CPU for a single invocation of this routine. See Thread Pool Keywords for details.

## Version History

Original | Introduced

## See Also

CINDGEN, COMPLEX, COMPLEXARR, DCINDGEN, DCOMPLEX, -DCOMPLEXARR