Help recursive function matlab code

Hello all

Please i need your help to code a recursive function.

udisc(k)=udisk(k-1) - tau*M*sign(phi(k));

where tau & M are positive constants and phi(k) is a function

Thank you so much

Best regards

Answer 1

[Thorsten]

You need to know the value of udisk for one k, like k=0 to define an end of the recursion. Assuming that udisk(0) = 1, the definition is straightforward

function u = udisk(k, tau, M)
if k == 1 % replace these two lines with the
  u = 1   % actual definition of udisk
else
  u = udisk(k-1, tau, M) - tau*M*sign(phi(k));
end

[lady bird]

thank u so much Thorsten for your help