function [ output ] = activationstep( input, type )
    if strcmp(type,'step')
       if(input>0)
           output=1;
       else
           output=0;
       end
    elseif strcmp(type,'sigmoid')
        output=input;
    elseif strcmp(type,'Dsigmoid')
        output=1;
    elseif strcmp(type,'tansigmoid')
        output=tanh(input);
    elseif strcmp(type,'linear')
        output=input;
    end
end

