Help to Generate triangle wave

Si i have this code for a square wave and i need to modify it to a triangle wave how??

t=-0.4:0.001:0.4;
T=0.2;
A=2;
Nt=length(t);
xt=zeros(1,Nt);
P=-0.4;
for n=1:Nt
    if t(n)<P+T/2
        xt(n)=A;
    else
        xt(n)=-A;
    end
    if t(n)>=P+T
        P=P+T;
    end
end

[Erivelton Gualter]

By the way, your code can be replaced by:

t = -0.4:0.001:0.4;    % Time Array
T = 0.2                % Wave Period
A = 2;                 % Amplitude
xt = A*square(2*pi*t/T);
plot(t,xt)

[taher zaouali]

Yes i know but my assignment is to use matematical equation.

Answer 1

[Erivelton Gualter]

There is a function you might use for this task called sawtooth. You might find some help in this page.

t = -.4:0.001:.4;               % Time Array
A = 2;                            
T = 0.2;                        
x = 2*sawtooth(2*pi*t/T, 1/2);  % sawtooth(T, xmax):
                                % xmax = 1/2: For triangle wave
plot(t,x)

[taher zaouali]

i know the function but i need to use a mathematical equation based on the one i wrote