change a vector field into contour lines

I have a program that graphs magntic field as vectors and I'd like to change the vector field to contour lines.

% Read the data from the CSV files
csvFile = 'C:\Users\paull\Desktop\magnetic probe data\coeff.csv';
data = readmatrix(csvFile);

csvFile2 = 'C:\Users\paull\Desktop\magnetic probe data\coeff.angle1.csv';
data2 = readmatrix(csvFile2);

textdata = readtable(csvFile, 'PreserveVariableNames', true);
probe = data(:, 2);
probNum = data(:, 5);
direction = table2cell(textdata(:, 8));  % Convert to cell array
zpos = data(:, 9);
rpos = data(:, 10);
pol = data(:, 13); % Polarity
ok = data(:, 14);
channel = data(:, 6);
NSRC = data(:, 12);
RC = 1 ./ data(:, 4);

angRaw = data2(2, :);
ang = angRaw(1:end-1);
angle = size(channel);

% finds the angle that each of the 10 channels have
for i = 1:192
    strValue = num2str(channel(i));
    if strcmp(strValue, 'NaN')
        angle(i) = 0;
        channel(i) = 0;
    else
        angle(i) = ang(channel(i));
    end
    if strcmp(num2str(rpos(i)), 'NaN')
        rpos(i) = 0;
    end
    if strcmp(num2str(zpos(i)), 'NaN')
        zpos(i) = 0;
    end
end

% Create a containers.Map to store the parameter values for each probe
DataMap = containers.Map('KeyType', 'double', 'ValueType', 'any');

% Iterate over the rows and populate the DataMap
for i = 1:size(data, 1)
    probeID = probe(i);  % Get the probe ID for the current row
    
    % Store the parameter values for the probe
    parameters = struct('probe', probe(i), 'direction', direction{i}, ...
        'zpos', zpos(i), 'rpos', rpos(i), 'pol', pol(i), 'ok', ok(i), ...
        'channel', channel(i), 'NSRC', NSRC(i), 'angle', angle(i), 'RC', RC(i));
    
    if ~isKey(DataMap, probeID)
        DataMap(probeID) = parameters;
    else
        % If the probe already exists in the map, append the new parameters to the existing ones
        existingParams = DataMap(probeID);
        updatedParams = catstruct(existingParams, parameters);
        DataMap(probeID) = updatedParams;
    end
end
%organizes the raw data
BzMap = containers.Map('KeyType', 'double', 'ValueType', 'any');

% Iterate over each probe and store its Bz measurements in the hashtable
for i = 1:192
    probeID = i;
    BzMap(probeID) = rawdata(i, :);
end
% Accessing Bz measurement for probe 10 at time step 480
probeID = 10;
timeStep = 492;
BzValue = rawdata(timeStep, probeID);

% Iterate over each probe and store its Bz measurements in the hashtable
for i = 1:192
    probeID = i;
    BzMap(probeID) = rawdata(i, :);
end

% Manually set the axis limits
xlim([0 0.3]); % Set the x-axis limits from 2 to 8
ylim([0 0.3]); % Set the y-axis limits from -1 to 1
mag = zeros(size(probNum));
hold on;
zm = size(rpos);
rm = size(rpos);

% Iterate over each probe and plot the corresponding unit vector
for i = 1:numel(probe)
    probeID = probe(i);
    params = DataMap(probeID);
    directionValue = params.direction;
    polarity = params.pol;  % Get the polarity of the probe
    
    % Check the direction value
    if strcmp(directionValue, 'z')
        % Plot a unit vector parallel to the z direction
        mag(i) = rawdata(timeStep, i) * NSRC(i);
        rm(i) = 0;
        zm(i) = 1 * mag(i);
        
        if abs(mag(i)) > 1
            mag(i) = 0;
        end
        
        if polarity < 0
            quiver3(zpos(i), rpos(i), 1, -1, 0, 0, 'LineWidth', 2, 'Color', 'b', 'AutoScaleFactor', (mag(i) * 2));
        else
            quiver3(zpos(i), rpos(i), 1, 1, 0, 0, 'LineWidth', 2, 'Color', 'b', 'AutoScaleFactor', (mag(i) * 2));
        end
    elseif strcmp(directionValue, 't')
        % Calculate the angle offset from the r direction
        angleValue = params.angle;
        x = sin(pi - angleValue);
        y = cos(pi - angleValue);
        z = 0;
        
        mag(i) = rawdata(timeStep, i) * NSRC(i) * pol(i) * -1;
        
        if abs(mag(i)) > 1
            mag(i) = 0;
        end
        
        rm(i) = -x * mag(i);
        zm(i) = y * mag(i);
        
        % Plot a unit vector at the specified angle offset from the r direction
        quiver3(zpos(i), rpos(i), 1, x, y, z, 'LineWidth', 2, 'Color', 'r', 'AutoScaleFactor', (mag(i) * 2));
    else
        % Plot a dot for probes with NaN direction values
        scatter3(zpos(i), rpos(i), 1, 'Marker', '.', 'MarkerFaceColor', 'k');
    end
end

% Adjust the aspect ratio of the plot
pbaspect([5 5 5]);

% Adjust the viewing angle
view(6,30);

[Cris LaPierre]

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