Hi can someone help me with my program demostrating Newton's method for system of nonlinear equations below. Line 45 gives an error saying return is outside the function and I don't know how to rectify that. I neewd this program to print differnt values of x until the differnce between previous x and present x is less than tol. Please help
Thank you from scipy import* tol=0.01 def swapRows(v,i,j): if len(v.getshape()) == 1: v[i],v[j] = v[j],v[i] else: temp = v[i].copy() v[i] = v[j] v[j] = temp def swapCols(v,i,j): temp = v[:,j].copy() v[:,j] = v[:,i] v[:,i] = temp def gaussPivot(a,b,tol=1.0e-12): n = len(b) # Set up scale factors s = zeros((n),float) for i in range(n): s[i] = max(abs(a[i,:])) for k in range(0,n-1): # Row interchange, if needed p = int(argmax(abs(a[k:n,k])/s[k:n])) + k if abs(a[p,k]) < tol: error.err('Matrix is singular') if p != k: swap.swapRows(b,k,p) swap.swapRows(s,k,p) swap.swapRows(a,k,p) # Elimination for i in range(k+1,n): if a[i,k] != 0.0: lam = a[i,k]/a[k,k] a[i,k+1:n] = a [i,k+1:n] - lam*a[k,k+1:n] b[i] = b[i] - lam*b[k] if abs(a[n-1,n-1]) < tol: error.err('Matrix is singular') for k in range(n-1,-1,-1): b[k] = (b[k] - dot(a[k,k+1:n],b[k+1:n]))/a[k,k] return b def newtonRaphson2(f,x,tol=1.0e-9): def jacobian(f,x): h = 1.0e-4 n = len(x) jac = zeros((n,n),float) f0 = f(x) for i in range(n): temp = x[i] x[i] = temp + h f1 = f(x) x[i] = temp jac[:,i] = (f1 - f0)/h return jac,f0 for i in range(30): jac,f0 = jacobian(f,x) if sqrt(dot(f0,f0)/len(x)) < tol: return x dx = gaussPivot(jac,-f0) x = x + dx if sqrt(dot(dx,dx)) < tol*max(max(abs(x)),1.0): return x print 'Too many iterations' def f(x): f = zeros((len(x)),float) f[0] = sin(x[0]) + x[1]**2 + log(x[2]) - 7.0 f[1] = 3.0*x[0] + 2.0**x[1] - x[2]**3 + 1.0 f[2] = x[0] + x[1] + x[2] - 5.0 return f x = array([1.0, 1.0, 1.0]) print newtonRaphson2(f,x) raw_input ("\nPress return to exit") ----------------------------------------- This email was sent using SquirrelMail. "Webmail for nuts!" http://squirrelmail.org/ _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor