# Log1p

Computes natural logarithm of vector elements that are increased by 1.

## Syntax

Fortran:

call vslog1p( n, a, y )

call vdlog1p( n, a, y )

C:

vsLog1p( n, a, y );

vdLog1p( n, a, y );

## Input Parameters

Name | Type | Description
--- | --- | ---
n | FORTRAN: INTEGER, INTENT(IN) C: int | Specifies the number of elements to be calculated.
a | FORTRAN: REAL, INTENT(IN) for vslog1p DOUBLE PRECISION, INTENT(IN) for vdlog1p C: const float* for vsLog1p const double* for vdLog1p | FORTRAN: Array, specifies the input vector a. C: Pointer to an array that contains the input vector a.

## Output Parameters

Name | Type | Description
--- | --- | ---
y | FORTRAN: REAL for vslog1p DOUBLE PRECISION for vdlog1p C: float* for vsLog1p double* for vdLog1p | FORTRAN: Array, specifies the output vector y. C: Pointer to an array that contains the output vector y.

Parent topic: Exponential and Logarithmic Functions