how can i create a monotonic function out of a Periodic function .like make a Monotonic sine function from 0 to 2pi

i used this loop to add the different every time but im not sure if its ok X1=sin(x); d=abs(diff(X1)); X2=X1; for j=2:numel(X1) X2(j)=X2(j-1)+d(j-1); end

[John D'Errico]

You need to define what that means. The sine function is NOT monotonic on that interval. Just wanting it to be monotonic has no meaning in mathematics. So explain what you need in clear terms.