Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 3/22/2024
Public

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Document Table of Contents

v?Exp

Computes an exponential of vector elements.

Syntax

call vsexp( n, a, y )

call vsexpi(n, a, inca, y, incy)

call vmsexp( n, a, y, mode )

call vmsexpi(n, a, inca, y, incy, mode)

call vdexp( n, a, y )

call vdexpi(n, a, inca, y, incy)

call vmdexp( n, a, y, mode )

call vmdexpi(n, a, inca, y, incy, mode)

call vcexp( n, a, y )

call vcexpi(n, a, inca, y, incy)

call vmcexp( n, a, y, mode )

call vmcexpi(n, a, inca, y, incy, mode)

call vzexp( n, a, y )

call vzexpi(n, a, inca, y, incy)

call vmzexp( n, a, y, mode )

call vmzexpi(n, a, inca, y, incy, mode)

Include Files

  • mkl_vml.f90

Input Parameters

Name

Type

Description

n

INTEGER, INTENT(IN)

Specifies the number of elements to be calculated.

a

DOUBLE PRECISION for vdexp, vmdexp

COMPLEX for vcexp, vmcexp

DOUBLE COMPLEX for vzexp, vmzexp

REAL, INTENT(IN) for vsexp, vmsexp

DOUBLE PRECISION, INTENT(IN) for vdexp, vmdexp

COMPLEX, INTENT(IN) for vcexp, vmcexp

DOUBLE COMPLEX, INTENT(IN) for vzexp, vmzexp

Array, specifies the input vector a.

inca, incy

INTEGER, INTENT(IN)

Specifies increments for the elements of a and y.

mode

INTEGER(KIND=8), INTENT(IN)

Overrides global VM mode setting for this function call. See vmlSetMode for possible values and their description.

Precision Overflow Thresholds for Real v?Exp Function
Data Type Threshold Limitations on Input Parameters
single precision a[i] < Ln( FLT_MAX )
double precision a[i] < Ln( DBL_MAX )

Precision overflow thresholds for the complex v?Exp function are beyond the scope of this document.

Output Parameters

Name

Type

Description

y

DOUBLE PRECISION for vdexp, vmdexp

COMPLEX for vcexp, vmcexp

DOUBLE COMPLEX for vzexp, vmzexp

REAL, INTENT(OUT) for vsexp, vmsexp

DOUBLE PRECISION, INTENT(OUT) for vdexp, vmdexp

COMPLEX, INTENT(OUT) for vcexp, vmcexp

DOUBLE COMPLEX, INTENT(OUT) for vzexp, vmzexp

Array, specifies the output vector y.

Description

The v?Exp function computes an exponential of vector elements.

Special Values for Real Function v?Exp(x)
Argument Result VM Error Status Exception
+0 +1    
-0 +1    
X > overflow + VML_STATUS_OVERFLOW OVERFLOW
X < underflow +0 VML_STATUS_UNDERFLOW UNDERFLOW
+ +    
- +0    
QNAN QNAN    
SNAN QNAN   INVALID

See Special Value Notations for the conventions used in the table below.

Special Values for Complex Function v?Exp(z)

RE(z)

i·IM(z)

-

 

-X

 

-0

 

+0

 

+X

 

+

 

NAN

 

+i·

 

+0+i·0

 

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

++i·QNAN

INVALID

QNAN+i·QNAN

INVALID

+i·Y +0·CIS(Y)         +·CIS(Y) QNAN+i·QNAN
+i·0 +0·CIS(0)   +1+i·0 +1+i·0   ++i·0 QNAN+i·0
-i·0 +0·CIS(0)   +1-i·0 +1-i·0   +-i·0 QNAN-i·0
-i·Y +0·CIS(Y)         +·CIS(Y) QNAN+i·QNAN

-i·

 

+0-i·0

 

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

++i·QNAN

INVALID

QNAN+i·QNAN

INVALID

+i·NAN

+0+i·0

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

QNAN+i·QNAN

INVALID

++i·QNAN

QNAN+i·QNAN

Notes:

  • raises the INVALID exception when real or imaginary part of the argument is SNAN

  • raises the INVALID exception on argument z=-+i·QNAN

  • raises the OVERFLOW exception and sets the VM Error Status to VML_STATUS_OVERFLOW in the case of overflow, that is, when both RE(z) and IM(z) are finite non-zero numbers, but the real or imaginary part of the exact result is so large that it does not meet the target precision.