zbrent

def analysis.numerov_solve.zbrent (   func,   x1,   x2,   tol,   itmax = 100,   trace = 0   ) Definition at line 38 of file numerov_solve.py. 00038 : 00039 "find zeros using the van Wijngaarden-Dekker-Brent method a la Numeric Recipes" 00040 a=x1; b=x2 00041 fa=func(a); fb=func(b) 00042 00043 assert fb*fa < 0.0, "Root must be bracketed in ZBRENT" 00044 fc=fb 00045 for iter in range(itmax): 00046 if trace: print iter, a, b, fa, fb 00047 if (fb*fc > 0.0): 00048 c=a 00049 fc=fa 00050 e=d=b-a 00051 if abs(fc) < abs(fb): 00052 a=b 00053 b=c 00054 c=a 00055 fa=fb 00056 fb=fc 00057 fc=fa 00058 tol1=2.0*1e-14*abs(b)+0.5*tol 00059 xm=0.5*(c-b) 00060 if abs(xm) <= tol1 or fb == 0.0: return b 00061 if abs(e) >= tol1 and abs(fa) > abs(fb): 00062 s=fb/fa 00063 if a==c: 00064 p=2.0*xm*s 00065 q=1.0-s 00066 else: 00067 q=fa/fc 00068 r=fb/fc 00069 p=s*(2.0*xm*q*(q-r)-(b-a)*(r-1.0)) 00070 q=(q-1.0)*(r-1.0)*(s-1.0) 00071 if p>0.0: q = -q 00072 p=abs(p) 00073 min1=3.0*xm*q-abs(tol1*q) 00074 min2=abs(e*q) 00075 if 2.0*p < min(min1,min2): 00076 e=d 00077 d=p/q 00078 else: 00079 d=xm 00080 e=d 00081 else: 00082 d=xm; e=d 00083 a=b 00084 fa=fb 00085 if abs(d) > tol1: 00086 b += d 00087 elif xm > 0.0: 00088 b+=tol1 00089 else: 00090 b-=tol1 00091 fb = func(b); 00092 00093 assert 0, "Maximum number of iterations exceeded in ZBRENT" 00094 def single_well_numerov_match(V0, dx, parity=1, overlapsize=5):

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