% -*- texinfo -*-
% @deftypefn {Function File} [@var{YY},@var{PS}] = mapstd (@var{XX},@var{ymean},@var{ystd})
% Map values to mean 0 and standard derivation to 1.
%
% @example
% [YY,PS] = mapstd(XX,ymean,ystd)
%
% Apply the conversion and returns YY as (YY-ymean)/ystd.
%
% [YY,PS] = mapstd(XX,FP)
%
% Apply the conversion but using an struct to inform target mean/stddev.
% This is the same of [YY,PS]=mapstd(XX,FP.ymean, FP.ystd).
%
% YY = mapstd('apply',XX,PS)
%
% Reapply the conversion based on a previous operation data.
% PS stores the mean and stddev of the first XX used.
%
% XX = mapstd('reverse',YY,PS)
%
% Reverse a conversion of a previous applied operation.
%
% dx_dy = mapstd('dx',XX,YY,PS)
%
% Returns the derivative of Y with respect to X.
%
% dx_dy = mapstd('dx',XX,[],PS)
%
% Returns the derivative (less efficient).
%
% name = mapstd('name');
%
% Returns the name of this convesion process.
%
% FP = mapstd('pdefaults');
%
% Returns the default process parameters.
%
% names = mapstd('pnames');
%
% Returns the description of the process parameters.
%
% mapstd('pcheck',FP);
%
% Raises an error if FP has some inconsistent.
% @end example
%
% @end deftypefn