Complex Sinwave to plot

Hello,

I'm asking how can I plot this kind of function ?

I wish to extract its mathematical expression.

I was thinking about creating a triangular wave first and add it to a sinwave ? Would that be possible ?

But I dont know how to start, I've already code on Matlab but I'm a begineer, so can I have some help to plot the triangle first ?

Answer 1

[Alan Stevens]

Like this

x = 0:0.1:4.56;
p = zeros(1,numel(x));
q = zeros(1,numel(x));
for i = 1:numel(x)
    p(i) = fn(x(i));
    q(i) = fn(x(i)+4.56);
end
plot(x,p,'b',x+4.56,q,'k'),grid
xlabel('x'),ylabel('p & q')
legend('p','q')

function h = fn(x)

           if x>=0 && x<=4.56
              h = 2*sin(2*pi*0.5*x)+1.1042*x;
           elseif x>4.56 && x<=9.12
              h = 2*sin(2*pi*0.5*(x-0.1151211265955))-1.1042*(x-0.1151211265955) ...
                  + 9.9376427230941;
            else 
              h = NaN; 
            end
end