分类准确率
% bestc:最佳的参数c
% bestg:最佳的参数g

% about the parameters of SVMcgForRegress
if nargin < 10
    msestep = 0.1;
end
if nargin < 7
    msestep = 0.1;
    v = 3;
    cstep = 1;
    gstep = 1;
end
if nargin < 6
    msestep = 0.1;
    v = 3;
    cstep = 1;
    gstep = 1;
    gmax = 5;
end
if nargin < 5
    msestep = 0.1;
    v = 3;
    cstep = 1;
    gstep = 1;
    gmax = 5;
    gmin = -5;
end
if nargin < 4
    msestep = 0.1;
    v = 3;
    cstep = 1;
    gstep = 1;
    gmax = 5;
