[file,path] = uigetfile("*.S2P");

filename = [path , file];

matrix = loads2p(filename);

frex = matrix(:,1);
for i = 1:numel(frex)
    if frex(i) > 1e4
        frex(i) = frex(i).*1e-9;
    end
end




figure(101)
lines = numel(findall(gcf, 'type','line'))/4+1;

[CC, LL, MM] = ndgrid({1,2,3,4}, {'-', ':', '-.', '--'}, {'none','+', 'o', '*', 'square', 'diamond'});
combinations = [CC(:), LL(:), MM(:)];
cols =     [0.3467    0.5360    0.6907
    0.9153    0.2816    0.2878
    0.4416    0.7490    0.4322
    1.0000    0.5984    0.2000];

heads = ["S11","S12","S22","S21"];
for i = 1:4
    subplot(2,2,i)
    hold on
    plot(frex,10*log10(abs(matrix(:,2*i)+1i.*matrix(:,2*i+1))),"Color",cols(combinations{lines,1},:),'DisplayName',file,'LineStyle',combinations{lines,2},'Marker',combinations{lines,3},'MarkerSize',3);
    if i == 2 || i == 3
        ylim([-6 0]);
    else
        ylim([-30 0]);
    end
    xlim([0 70]);
    title(heads(i))
    xlabel('Frequency in GHZ');
    ylabel('Attenuation in dB');
    legend
end
sgtitle(['S-Parameter']);



function matrix = loads2p(filepath)
startRow = 2;

%% Read columns of data as text:
% For more information, see the TEXTSCAN documentation.
formatSpec = '%20s%25s%23s%23s%23s%23s%23s%23s%23s%s%[^\n\r]';

%% Open the text file.
fileID = fopen(filepath,'r');

%% Read columns of data according to the format.
% This call is based on the structure of the file used to generate this code. If an error occurs for a different file, try regenerating the code from the Import Tool.
dataArray = textscan(fileID, formatSpec, 'Delimiter', '', 'WhiteSpace', '', 'TextType', 'string', 'HeaderLines' ,startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n');

%% Close the text file.
fclose(fileID);

%% Convert the contents of columns containing numeric text to numbers.
% Replace non-numeric text with NaN.
raw = repmat({''},length(dataArray{1}),length(dataArray)-1);
for col=1:length(dataArray)-1
    raw(1:length(dataArray{col}),col) = mat2cell(dataArray{col}, ones(length(dataArray{col}), 1));
end
numericData = NaN(size(dataArray{1},1),size(dataArray,2));

for col=[1,2,3,4,5,6,7,8,9,10]
    % Converts text in the input cell array to numbers. Replaced non-numeric text with NaN.
    rawData = dataArray{col};
    for row=1:size(rawData, 1)
        % Create a regular expression to detect and remove non-numeric prefixes and suffixes.
        regexstr = '(?<prefix>.*?)(?<numbers>([-]*(\d+[\,]*)+[\.]{0,1}\d*[eEdD]{0,1}[-+]*\d*[i]{0,1})|([-]*(\d+[\,]*)*[\.]{1,1}\d+[eEdD]{0,1}[-+]*\d*[i]{0,1}))(?<suffix>.*)';
        try
            result = regexp(rawData(row), regexstr, 'names');
            numbers = result.numbers;

            % Detected commas in non-thousand locations.
            invalidThousandsSeparator = false;
            if numbers.contains(',')
                thousandsRegExp = '^[-/+]*\d+?(\,\d{3})*\.{0,1}\d*$';
                if isempty(regexp(numbers, thousandsRegExp, 'once'))
                    numbers = NaN;
                    invalidThousandsSeparator = true;
                end
            end
            % Convert numeric text to numbers.
            if ~invalidThousandsSeparator
                numbers = textscan(char(strrep(numbers, ',', '')), '%f');
                numericData(row, col) = numbers{1};
                raw{row, col} = numbers{1};
            end
        catch
            raw{row, col} = rawData{row};
        end
    end
end


%% Replace non-numeric cells with NaN
R = cellfun(@(x) ~isnumeric(x) && ~islogical(x),raw); % Find non-numeric cells
raw(R) = {NaN}; % Replace non-numeric cells

%% Create output variable
matrix = cell2mat(raw);
%% Clear temporary variables
clearvars filename startRow formatSpec fileID dataArray ans raw col numericData rawData row regexstr result numbers invalidThousandsSeparator thousandsRegExp R;

end