How should I generate a Matlab code for tenttone using the following information

TENTTONE Generates a triangularly shaped tone. 
%   S = TENTTONE(F,FS,LEN,PHASE) generates signal vector S that represents
%   the samples of a triangularly shaped tone with frequency F in [Hz] and
%   duration LEN in [sec]. Parameter FS determines the assumed underlying
%   sampling frequency in [Hz]. Parameter PHASE is an optional argument
%   that allows an explicit specification of a phase shift. Parameter
%   PHASE defaults to zero if omitted.
%
%   EXAMPLE: FS=8000; S=tenttone(440,FS,0.5,pi/4);
%            sound(0.9*S,FS);
%   
%   See also RECTTONE and SINETONE.

% check for optional parameter
if nargin<4; PHASE=0; end
if nargin<4; PHASE=0; end

[Walter Roberson]

Please do not tag individuals.

http://www.mathworks.co.uk/matlabcentral/answers/43073-a-guide-to-tags

[Walter Roberson]

How would you generate one period of a triangle wave?

Answer 1

[Soumya Saxena]

I understand that you want to plot triangular wave forms. You may refer to the "sawtooth" function to plot a triangular wave. Please refer to the following documentation:

https://www.mathworks.com/help/signal/ref/sawtooth.html

Another suggestion is to use "tripuls" function. For details you can refer to the following:

https://www.mathworks.com/help/signal/ref/tripuls.html

For examples on how to generate pulses, you may refer to this page:

http://www.mathworks.com/help/signal/examples/signal-generation-and-visualization.html#zmw57dd0e50

Answer 2

[Image Analyst]

Use linspace(). Here, I did half of it for you. I trust you can do the other half.

% Program to create a wave file with variable amplitude and pitch.
% Initialization / clean-up code.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;

% Create the filename where we will save the waveform.
folder = pwd;
baseFileName = 'Test_Wave.wav';
fullFileName = fullfile(folder, baseFileName);
fprintf('Full File Name = %s\n', fullFileName);

% Set up the time axis:
Fs = 12000;
duration = 1; % seconds.
t = 1 : duration * Fs; % 2 seconds

% Set up the period (pitch, frequency):
T = 13; % Constant pitch if you use this.
% T = linspace(25, 8, length(t)); % Pitch changes if you use this.

% Create the maximum amplitude:
Amplitude = 32767 * ones(1, length(t));
% Make a ramp
halfWay = round(length(t) / 2);
Amplitude(1:halfWay) = linspace(0, 32767, halfWay);

% Construct the waveform:
y = int16(Amplitude .* sin(2.*pi.*t./T));
% y = abs(int16(Amplitude .* sin(2.*pi.*x./T)));

% Plot the waveform:
plot(t, y, 'b-');
title('Waveform', 'FontSize', fontSize);
xlabel('Time', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);
grid on;
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
fprintf('Writing file %s...\n', fullFileName);

% Write the waveform to a file:
audiowrite(fullFileName, y, Fs);

% Play the sound as many times as the user wants.
playAgain = true;
counter = 1;
while playAgain
  % Play the sound that we just created.
  fprintf('Playing file %s   %d times...\n', fullFileName, counter);
  player = audioplayer(y, Fs);
  play(player);
  % Ask user if they want to play the sound again.
  promptMessage = sprintf('You have played the sound %d times.\nDo you want to play the sound again?', counter);
  titleBarCaption = 'Continue?';
  button = questdlg(promptMessage, titleBarCaption, 'Yes', 'No', 'Yes');
  if strcmpi(button, 'No')
    playAgain = false;
    break;
  end
  counter = counter + 1;
end

% Alert user that we are done.
message = sprintf('Done playing %s.\n', fullFileName);
fprintf('%s\n', message);
promptMessage = sprintf('Done playing %s.\nClick OK to close the window\nor Cancel to leave it up.', fullFileName);
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'OK', 'Cancel', 'OK');
if strcmpi(button, 'OK')
  close all;  % Close down the figure.
end