How to generate dataset in one file instead of separate frams?

I have a code below which save data on different frame but i want to save in one file because i need to convert them in HDF5 later on. the code is taken from link:

https://www.mathworks.com/help/deeplearning/ug/modulation-classification-with-deep-learning.html

dataDirectory = "E:\Thesis\SNR-dataset\new";

disp("Data file directory is " + dataDirectory)

%%

fileNameRoot = "frame";

% Check if data files exist

dataFilesExist = false;

if exist(dataDirectory,'dir')

files = dir(fullfile(dataDirectory,sprintf("%s*",fileNameRoot)));

if length(files) == numModulationTypes*numFramesPerModType

dataFilesExist = true;

end

end

if ~dataFilesExist

disp("Generating data and saving in data files...")

[success,msg,msgID] = mkdir(dataDirectory);

if ~success

error(msgID,msg)

end

for modType = 1:numModulationTypes

fprintf('%s - Generating %s frames\n', ...

datestr(toc/86400,'HH:MM:SS'), modulationTypes(modType))

label = modulationTypes(modType);

numSymbols = (numFramesPerModType / sps);

dataSrc = helperModClassGetSource(modulationTypes(modType), sps, 2*spf, fs);

modulator = helperModClassGetModulator(modulationTypes(modType), sps, fs);

if contains(char(modulationTypes(modType)), {'B-FM','DSB-AM','SSB-AM'})

% Analog modulation types use a center frequency of 100 MHz

channel.CenterFrequency = 100e6;

else

% Digital modulation types use a center frequency of 902 MHz

channel.CenterFrequency = 902e6;

end

for p=1:numFramesPerModType

% Generate random data

x = dataSrc();

%size(x)

% Modulate

y = modulator(x);

%size(y)

% Pass through independent channels

release(channel)

rxSamples = channel(y);

% Remove transients from the beginning, trim to size, and normalize

frame = helperModClassFrameGenerator(rxSamples, spf, spf, transDelay, sps);

% Save data file

fileName = fullfile(dataDirectory,...

sprintf("%s%s%03d",fileNameRoot,modulationTypes(modType),p));

save(fileName,"frame","label")

end

end

else

disp("Data files exist. Skip data generation.")

end%%