= PDAF_generate_rndvec = 

This page documents the routine `PDAF_generate_rndvec` of PDAF. It was added in PDAF V3.1.

The routine returns a random vector with a specified distribution

The interface is the following: 
{{{
  SUBROUTINE PDAF_generate_rndvec(len, vec, stddev, dist, iseed)
}}}
with the following arguments:
{{{
  integer, intent(in) :: len           ! Length of vector to perturb
  real, intent(inout) :: vec(:)        ! vector to be perturbed
  real, intent(in)    :: stddev        ! Standard deviation of lognormal distribution
  integer, intent(in) :: dist          ! Distribution: 
                                       !   (1) Normal, N(vec, stddev^2)
                                       !   (2) Log-normal, logN(vec, stddev^2)
                                       !   (3) uniform: vec + stddev*U(0,1))
                                       !   (4) uniform: vec + stddev*U(-1,1))
                                       !   (5) Laplace
  integer, intent(in) :: iseed(4)      ! Seed for dlarnv (last entry has to be odd)
}}}

**Note:**
 * The values of `iseed` are set by the user to control the random number generation. 
 * PDAF's random number generation uses the LAPACK function DLARNV.