function s=interpoLin(f,X,t)
    s=f(t)
    for i=2:length(X)
        if X(i-1) < t & t < X(i) 
            s=(f(X(i))-f(X(i-1)))/(X(i)-X(i-1))*(t-X(i))+f(X(i))
        end
    end
endfunction

function y=f(x)
    y=exp(x)
endfunction

function y=g(x)
    y=cos(x)
endfunction
