The SQRT function computes the square root of *X*.

## Examples

To find the square root of 145 and store the result in variable S, enter:

S = SQRT(145)

## Syntax

*Result* = SQRT(*X*)

## Return Value

Returns the square root of *X*.

## Arguments

### X

The value for which the square root is desired. If *X* is double-precision floating-point or complex, the result is of the same type. All other types are converted to single-precision floating-point and yield floating-point results. When applied to complex numbers, *z* = *x*+*iy*:

The ambiguous sign is taken to be the same as the sign of *y*. The result has the same structure as *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 |