I have to generate a matlab code for generating triangular wave with monotonically increasing and monotonically decreasing amplitude. That means the triangle should go on reduce its size with increasing time. plz can any one help me in this regard
John Michell answered .
2025-11-20
% Creates triangle waves two ways, one using repmat() and
% one using sawtooth() from the Signal Processing Toolbox.
format longg;
format compact;
clc; % Clear command window.
workspace; % Make sure the workspace panel is showing.
fontSize = 15;
close all; % Close figures from a prior run of this demo.
% If you have the signal Processing Toolbox, you can do
figure;
x=-30 : 0.01 : 30;
f=@(x) 10 * sawtooth(x ,0.5) + 5;
line(x,f(x),'color','r', 'linewidth',2.5)
grid on;
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Give a name to the title bar.
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off')
% If you don't have the Signal Processing Toolbox, you can try this:
% Define some parameters that define the triangle wave.
elementsPerHalfPeriod = 30; % Number of elements in each rising or falling section.
amplitude = 5; % Peak-to-peak amplitude.
verticalOffset = -2; % Also acts as a phase shift.
numberOfPeriods = 4; % How many replicates of the triangle you want.
% Construct one cycle, up and down.
risingSignal = linspace(0, amplitude, elementsPerHalfPeriod);
fallingSignal = linspace(amplitude, 0, elementsPerHalfPeriod);
% Combine rising and falling sections into one single triangle.
oneCycle = [risingSignal, fallingSignal(2:end-1)] + verticalOffset;
x = 0 : length(oneCycle)-1;
% Now plot the triangle.
figure;
subplot(3, 1, 1);
plot(x, oneCycle, 'bo-');
grid on;
title('One Cycle of the Triangle', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Give a name to the title bar.
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off')
% Now replicate this cycle several (numberOfPeriods) times.
triangleWaveform = repmat(oneCycle, [1 numberOfPeriods]);
x = 0 : length(triangleWaveform)-1;
% Now plot the triangle wave.
subplot(3, 1, 2);
plot(x, triangleWaveform, 'bo-');
grid on;
title('Several Cycles of the Triangle', 'FontSize', fontSize);
% Now blur it to smooth it out:
windowWidth = 9;
smoothTriangleWave = conv(triangleWaveform, ones(1,windowWidth)/windowWidth, 'same');
subplot(3, 1, 3);
plot(x, smoothTriangleWave, 'bo-');
grid on;
title('Smoothed Triangle Wave', 'FontSize', fontSize);