;******************************************************************************
;+
; NAME:
;	RANDOMCOVAR
;
; PURPOSE:
;	Generates correlated multivariate random deviates using
;	RANDLIB 1.3 (University of Texas MD Anderson Cancer Center)
;
; CALLING SEQUENCE:
;	Result = RANDOMCOVAR(Mean, Covar, Ndeviates)
;
; INPUTS:
;	Mean:	Array of mean parameter values
;	Covar:	Covariance matrix
;	Ndeviates: Number of deviates to return for each parameter
;
; OUTPUTS:
;	Result: Ndeviates x Npar array where Npar = N_ELEMENTS(Mean)
;
; EXAMPLE:
;	deviates = RANDOMCOVAR([10., 10.], [10., 5., 5., 10.], 1000)
;
; COMMENTS:
;	This routine calls the shared library randomcovar.so, which
;	must be located in the current directory.  In future updates
;	this library will be moved to a standard directory and grabbed
;	via an environment variable.
;
; MODIFICATION HISTORY:
; 	Written by:	R. Marzke, 11/16/2006
;-
;******************************************************************************

function randomcovar, mean, covar, ndeviates

  np = long(n_elements(mean))
  np2 = np^2
  ndevarr = np * ndeviates

  ccovar = fltarr(np2)
  ccovar[*] = covar

  work = fltarr(np)
  temp = fltarr(np)

  nparam = 1 + np + np2 
  param = fltarr(nparam)

  deviates = fltarr(ndevarr)

  success = call_external('randomcovar.so', 'randomcovar', $
                           float(mean), ccovar, long(np), long(ndeviates), $
                           work, temp, param, deviates, $
                           /AUTO_GLUE) 

  dev2d = fltarr(np, ndeviates)
  dev2d[*] = deviates

  return, transpose(dev2d)

end