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Re: Using max when there is symbolic variable
Posted:
Jun 30, 2013 3:49 AM


On Saturday, June 29, 2013 5:01:09 PM UTC+5:30, Maya wrote: > Hi, > > > > I am trying to solve this problem: > > p_i=max(0,(1+sqrt(14*c_i*d_i+4*(c_id_i)*c_i*d_i/(x*a_i))/2*c_i*d_i) if c_i>d_i > > and p_i=0 otherwise. p_i, c_i,d_i are diagonal elements of matrices P, C, D and A. I need to find x and after that to calculate p_i, but I do not know how to implement max because at first x is a symbolic variable. > > > > I would appreciate if anyone could help me. > > Maya
syms c_i d_i a_i x >> expand(1+sqrt(14*c_i*d_i+4*(c_id_i)*c_i*d_i/(x*a_i))/2*c_i*d_i) ans = (c_i*d_i*((4*c_i^2*d_i)/(a_i*x)  (4*c_i*d_i^2)/(a_i*x)  4*c_i*d_i + 1)^(1/2))/2  1
solve(1+sqrt(14*c_i*d_i+4*(c_id_i)*c_i*d_i/(x*a_i))/2*c_i*d_i) ans = (c_i*d_i*(4*c_i  4*d_i))/(a_i*(4*c_i*d_i + 4/(c_i^2*d_i^2)  1))
this the value of x if p_i=0
i dont understand your problem exactly....
you want to find max(0,somenumber). is it?
here somenumber is a variable.... is it?



