function mnimportdata( filename, Freq, Abs, Phase, dataname, datatype, varargin )
data = importdata(filename);
if mnismember(varargin,'density')
    error('density should be change to diaggui')
end
    
if mnismember(varargin,'diaggui')
    divise = 'diaggui';
else
    divise = 'agilent';
end

if strcmp(datatype,'tf')
if isstruct(data)
    Freq(dataname) = data.data(:,1);
    Abs(dataname) = data.data(:,2);
    Phase(dataname) = data.data(:,3);
else
    Freq(dataname) = data(:,1);
    Abs(dataname) = data(:,2);
    Phase(dataname) = data(:,3);
end
else
if isstruct(data)
    Freq(dataname) = data.data(:,1);
    if strcmp(divise, 'agilent')
        Abs(dataname) = sqrt(data.data(:,2)/2); %convert to RMS
    else
        Abs(dataname) = (data.data(:,2));
    end
else
    Freq(dataname) = data(:,1);
    if strcmp(divise, 'agilent')
        Abs(dataname) = sqrt(data(:,2)/2); %convert to RMS
    else
        Abs(dataname) = (data(:,2));
    end
end
end