** Recursive function used by QUAD . **

** [Q,cnt] = quadstp(F,a,b,tol,lev,fa,fc,fb,Q0) tries to **

** approximate the integral of f(x) from a to b to within a **

** relative error of tol. F is a string containing the name **

** of f. The remaining arguments are generated by quad or by **

** the recursion. lev is the recursion level. **

** fa = f(a). fc = f((a+b)/2). fb = f(b). **

** Q0 is an approximate value of the integral. **

** See also QUAD and QUAD8 . **

** **