scale_snn.m

来自「神经网络的工具箱, 神经网络的工具箱,」· M 代码 · 共 82 行

function [y, sc] = scale_snn(x, sc, s)
%SCALE_SNN scale values.
%
% Syntax
%
%  1.  [y, sc] = scale_snn(x, scaling_name)
%  2.  y = scale_snn(x, sc);
%
% Description
%
%  1. SCALE_SNN(x, scaling_name) takes
%    x            - values which scaling parameters are computed from.
%    scaling_name - scaling function. Supported scaling functions are:
%                   SC_EXP_SNN      - exp(x)
%                   SC_INV_SNN      - 1/x
%                   SC_LOG_SNN      - log(x)
%                   SC_MEANZERO_SNN - x-mean(x)
%                   SC_MONEONE_SNN  - linear mapping on [-1, 1]
%                   SC_SQRT_SNN     - sqrt(x)
%                   SC_STDONE_SNN   - x/std(x)
%                   SC_ZEROONE_SNN  - linear mapping on [0, 1]
%  and returns
%    y   - scaled values.
%    sc  - sc_struct containing scaling information.
%
%
%  2. SCALE_SNN(x, sc) takes
%    x   - values to be scaled.
%    sc  - sc_struct containing scaling information to be used.
%  and reutrns
%    y   - scaled values.
%
% Examples
%
%  x = [1 2 3; 4 5 6] 
%  [y(1,:), sc1] = scale_snn(x(1,:), 'sc_meanzero_snn')
%  [y(1,:), sc2] = scale_snn(y(1,:), 'sc_sqrt_snn')
%  [y(2,:), sc3] = scale_snn(x(2,:), 'sc_sqrt_snn')
%
%  scale_snn([0 1 2], sc1)
%
%  xinv = invscale_snn(y, {[sc1 sc2]; sc3})
%  
%  
% See also
%
%  INVSCALE_SNN
%

%   NOT DOCUMENTED (use INVSCALE_SNN instead):
%   x = scale_snn(y, sc, 'inv')
%

%#function sc_exp_snn sc_inv_snn sc_log_snn sc_meanzero_snn 
%#function sc_moneone_snn sc_sqrt_snn sc_stdone_snn sc_zeroone_snn 
if (nargin == 2)
   if isstr(sc)                               % scale_snn(x, scaling_name)
      [y, sc] = feval(sc, x);
   elseif iscell(sc)
      for k = 1:size(x, 1)
	  tmp = x(k,:);
          for i = 1:prod(size(sc{k}))
              tmp = feval(sc{k}(i).name, tmp, sc{k}(i).parameters);
	  end
          y(k,:) = tmp;
      end
   else
      for i = 1:prod(size(sc))
          x = feval(sc(i).name, x, sc(i).parameters);
      end
      y = x;
   end
elseif (nargin == 3)
   if strcmp('inv', s)
      y = invscale_snn(x, sc);
   else
      error('SCALE_SNN: 3rd argument must be ''inv''.');
   end
else
   error('SCALE_SNN: incorrect number of input arguments');
end