Migrating user accounts from one AD domain to another AD Domain using Powershell

Got the opportunity to migrate the users from one domain to another domain. Users should migrate in Nintex DB too.

$nwcmd = 'C:\Program Files\Nintex\Nintex Workflow 2010\NWAdmin.exe'
$nwarg1 = '-o'
$nwarg2 = 'MigrateUser'
$nwarg3 = '-oldUser'
$nwarg4 = '-newUser'
$errorstatus=$ErrorActionPreference

Add-PSSnapin Microsoft.SharePoint.PowerShell -ea silentlycontinue

$m = [Microsoft.SharePoint.Administration.Claims.SPClaimProviderManager]::Local
Function Get-SPClaim {
    param ([string]$user)
    $claim = New-SPClaimsPrincipal -identity $user -IdentityType "WindowsSamAccountName"
    return $m.EncodeClaim($claim)
}



function MigrateUserOrGroups($migrationType, $csvFile)
{
   #Getting the SPFarm object
   $farm = Get-SPFarm

   Write-Host $migrationType
   #Checking whether the user input the type of Migration as Group
   if($migrationType -eq "Group"){
   Import-Csv $csvFile | ForEach-Object{
      Write-Host "Migrating Group" $_.oldlogin "to" $_.newlogin -ForegroundColor Green
      $farm.MigrateGroup($_.oldlogin, $_.newlogin)
     
       }
      }
     
    #Checking whether the user input the type of Migration as User
    if($migrationType -eq "User")
    {

        Import-Csv $csvFile | ForEach-Object{
       
        $olduser= Get-SPClaim($_.oldlogin);
            $newuser= Get-SPClaim($_.newlogin);
            $oldloginname=$_.oldlogin
            try
            {
                $ErrorActionPreference="stop"
               
                Write-Host $newuser
                Write-Host "Migrating User" $_.oldlogin "to" $_.newlogin -ForegroundColor Green
                $farm.MigrateUserAccount( $olduser, $newuser, $false )
                write-host $nwcmd $nwarg1 $nwarg2 $nwarg3 """$olduser""" $nwarg4 """$newuser"""
                & $nwcmd $nwarg1 $nwarg2 $nwarg3 $olduser $nwarg4 $newuser
               
             }
             catch
             {
                write-host "Exception occured for migrating user"  $oldloginname " Message: $($_.Exception.Message)" -ForegroundColor Red
             }
             finally
             {
                $ErrorActionPreference=$errorstatus
             }
               
        }    
    }
     
   Write-Host "Migration Completed" -ForegroundColor Cyan
 
 
 
}

MigrateUserOrGroups $args[0] $args[1]
Follow below links
http://blogs.msdn.com/b/sowmyancs/archive/2012/01/07/migrate-users-groups-powershell-script.aspx?PageIndex=2
http://sharepoint.stackexchange.com/questions/118424/how-to-migrate-ad-domain-groups-in-sharepoint-2010