Routines (alphabetical) > Routines: S > SINH

# SINH

The SINH function returns the hyperbolic sine of X.

## Examples

To find the hyperbolic sine of each element in the array [.5, .2, .4] and print the result, enter:

PRINT, SINH([.5, .2, .4])

To plot the SINH function between 0 and 2π with 100 intervals, enter:

X = 2*!PI/100 * FINDGEN(100)
PLOT, X, SINH(X)

Note: !PI is a read-only system variable that contains the single-precision value of π.

## Syntax

Result = SINH(X)

## Return Value

Returns the double-precision floating-point, complex or single-precision floating-point value.

## Arguments

### X

The angle for which the hyperbolic sine is desired, specified in radians. If X is double-precision floating or complex, the result is of the same type. All other types are converted to single-precision floating-point and yield floating-point results. SINH is defined as:

sinh x = (eu - e-u) / 2

If X is an array, the result has the same structure, with each element containing the hyperbolic sine 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

ASIN, SIN