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    Metadata details:
    filename: vl_simplenn.m
    path of file: ./repos/TADT/utils/matconvnet/matlab/simplenn
    
    the code of the file until where you have to start completion: function res = vl_simplenn(net, x, dzdy, res, varargin)
%VL_SIMPLENN  Evaluate a SimpleNN network.
%   RES = VL_SIMPLENN(NET, X) evaluates the convnet NET on data X.
%   RES = VL_SIMPLENN(NET, X, DZDY) evaluates the convnent NET and its
%   derivative on data X and output derivative DZDY (foward+bacwkard pass).
%   RES = VL_SIMPLENN(NET, X, [], RES) evaluates the NET on X reusing the
%   structure RES.
%   RES = VL_SIMPLENN(NET, X, DZDY, RES) evaluates the NET on X an
    
function handle computing the block.
%     - `layer.backward` is a function handle computing the block derivative.
%
%     The first function is called as
%
%          res(i+1) = layer.forward(layer, res(i), res(i+1))
%
%     where RES is the structure array specified before. The second function is
%     called as
%
%          res(i) = layer.backward(layer, res(i), res(i+1))
%
%     Note that the `layer` structure can contain additional custom
%     fields if needed.
%
%   See also: dagnn.DagNN, VL_SIMPLENN_TIDY(),
%   VL_SIMPLENN_DISPLAY(), VL_SIMPLENN_MOVE().

% Copyright (C) 2014-15 Andrea Vedaldi.
% All rights reserved.
%
% This file is part of the VLFeat library and is made available under
% the terms of the BSD license (see the COPYING file).

opts.conserveMemory = false ;
opts.sync = false ;
opts.mode = 'normal' ;
opts.accumulate = false ;
opts.cudnn = true ;
opts.backPropDepth = +inf ;
opts.skipForward = false ;
opts.parameterServer = [] ;
opts.holdOn = false ;
opts = vl_argparse(opts, varargin);

n = numel(net.layers) ;
assert(opts.backPropDepth > 0, 'Invalid `backPropDepth` value (!>0)');
backPropLim = max(n - opts.backPropDepth + 1, 1);

if (nargin <= 2) || isempty(dzdy)
  doder = false ;
  if opts.skipForward
    error('simplenn:skipForwardNoBackwPass', ...
      '`skipForward` valid only when backward pass is computed.');
  end