function varargout = pm_restore_ramp(varargin)
% 
% Restores linear phase-ramps in the x-, y- and z-direction 
% that has previously been removed from pm by pm_estimate_ramp.
% FORMAT: pm = pm_estimate_ramp(pm,mask,ramps)
%
% Input:
% pm     : 2 or 3D phasemap that has been unwrapped and
%          that has had its ramps removed by pm_remove_ramp 
% mask   : Mask that indicates which voxels are worth
%          bothering with and which are not.
% ramps  : 3x1 vector signifying the slope of the ramps in
%          the x-, y- and z-directions. This SHOULD be the
%          values returned by a previous call to pm_estimate_ramp.
%
% Output: 
% pm     : Same as pm in, but with linear ramps restored.
%
% This routine was written on the suggestion of Mark J, and will 
% potentially improve performance of subsequent phase-unwrapping.
% I haven't actually found it particularly helpful, and it may
% simply have been a sneaky fMRIB attempt to delay the SPM 
% phasemap toolbox.
%__________________________________________________________________
% Jesper Andersson 30/9-03
%_______________________________________________________________________
% Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging

% Jesper Andersson 
% $Id: pm_restore_ramp.m 1317 2008-04-08 16:16:38Z chloe $

error('mex-function pm_restore_ramp.c not compiled');