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#   Copyright (c) 2012 Christophe Dutang                                                                                                  
#                                                                                                                                                                        
#   This program is free software; you can redistribute it and/or modify                                               
#   it under the terms of the GNU General Public License as published by                                         
#   the Free Software Foundation; either version 2 of the License, or                                                   
#   (at your option) any later version.                                                                                                            
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#   This program is distributed in the hope that it will be useful,                                                             
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#   GNU General Public License for more details.                                                                                    
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#   Free Software Foundation, Inc.,                                                                                                              
#   59 Temple Place, Suite 330, Boston, MA 02111-1307, USA                                                             
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### utility functions for step functions in GNE
###
###         R functions
### 


#step functions


#no relaxation steps (pure classic fixed point algorithms)
purestep <- function(k) 1


#constant-decreasing steps
decrstep <- function(k, param) ifelse(k <= param, 1/2, 1/2/(k-param))

decrstep5 <- function(k) decrstep(k, 5)

decrstep10 <- function(k) decrstep(k, 10)

decrstep20 <- function(k) decrstep(k, 20)