def spline_smoothing(self, sigma=None, lam=None, **kwargs): """ Cubic Spline Interplation sigma: phase bin error bars lam: (0,1], 1 = maximize fitting through control points (knots), 0 = minimize curvature of spline """ tdata = self.bins ydata = u.normalize(self.data, simple=True) N = len(ydata) noise = self.getOffpulseNoise() if lam is None or (lam > 1 or lam <= 0): lam = 1 - noise**2 mu = 2 * float(1 - lam) / (3 * lam) ### Define knot locations # Rotate the pulse so the peak is at the edges of the spline shift = -np.argmax(ydata) yshift = np.roll(ydata, shift) # Add periodic point tdata = np.concatenate((tdata, [tdata[-1] + np.diff(tdata)[0]])) yshift = np.concatenate((yshift, [yshift[0]])) knots = u.subdivide(tdata, yshift, noise, **kwargs) knots = np.array(np.sort(knots), dtype=np.int) knots = np.concatenate(([0], knots, [N])) #Add endpoints if sigma is None: setsigma = True #for passnum in range(2): while True: Nknots = len(knots) Narcs = Nknots - 1 t = np.array(tdata[knots], dtype=np.float) # Determine the knot y-values. y = np.zeros_like(t) y[0] = yshift[0] y[-1] = yshift[-1] for i in range(1, len(knots) - 1): knotL = knots[i - 1] knotR = knots[i + 1] dt = tdata[knotL:knotR] dy = yshift[knotL:knotR] p = np.polyfit( dt, dy, 3 ) #Fit a preliminary cubic over the data to place the point. f = np.poly1d(p) y[i] = f(tdata[knots[i]]) if setsigma: sigma = np.ones(len(y), dtype=np.float) Sigma = np.diag(sigma[:-1]) #matrix # Smoothing with Cubic Splines by D.S.G. Pollock 1999 h = t[1:] - t[:-1] r = 3.0 / h f = np.zeros_like(h) p = np.zeros_like(h) #q = np.zeros_like(h) p[0] = 2 * (h[0] + h[-1]) #q[0] = 3*(y[1] - y[0])/h[0] - 3*(y[-1] - y[-2])/h[-1] #note the indices f[0] = -(r[-1] + r[0]) for i in range(1, Narcs): p[i] = 2 * (h[i] + h[i - 1]) #q[i] = 3*(y[i+1] - y[i])/h[i] - 3*(y[i] - y[i-1])/h[i-1] f[i] = -(r[i - 1] + r[i]) # Build projection matrices R = np.zeros((Narcs, Narcs)) Qp = np.zeros((Narcs, Narcs)) for i in range(Narcs): #for j in range(Narcs): # if i == j: R[i, i] = p[i] Qp[i, i] = f[i] if i != Narcs - 1: R[i + 1, i] = h[i] R[i, i + 1] = h[i] Qp[i + 1, i] = r[i] Qp[i, i + 1] = r[i] R[0, -1] = h[-1] R[-1, 0] = h[-1] Qp[0, -1] = r[-1] Qp[-1, 0] = r[-1] Q = np.transpose(Qp) A = mu * np.dot(np.dot(Qp, Sigma), Q) + R b = np.linalg.solve(A, np.dot(Qp, y[:-1])) d = y[:-1] - mu * np.dot(np.dot(Sigma, Q), b) a = np.zeros(Narcs) c = np.zeros(Narcs) i = Narcs - 1 a[i] = (b[0] - b[i]) / (3 * h[i]) for i in range(Narcs - 1): a[i] = (b[i + 1] - b[i]) / (3 * h[i]) i = Narcs - 1 c[i] = (d[0] - d[i]) / h[i] - a[i] * h[i]**2 - b[i] * h[i] for i in range(Narcs - 1): c[i] = (d[i + 1] - d[i]) / h[i] - a[i] * h[i]**2 - b[i] * h[i] # Build polynomials S = [] for i in range(Narcs): S.append(np.poly1d([a[i], b[i], c[i], d[i]])) ytemp = np.zeros_like(yshift) for i in range(Narcs): ts = np.arange(t[i], t[i + 1]) hs = ts - t[i] yS = S[i](hs) ytemp[int(t[i]):int(t[i + 1])] = yS ytemp[-1] = ytemp[0] resids = yshift - ytemp #print resids,noise rms_resids = u.RMS(resids) #inds = np.where(np.abs(resids)>4*rms_resids)[0] inds = np.where( np.logical_and(yshift > 3 * noise, np.abs(resids) > 4 * rms_resids) )[0] #require the intensity to be "significant", and the residuals if len(inds) == 0: break #newinds = np.sort(np.abs(resids)) newinds = np.argsort(np.abs(resids)) #print np.argmax(np.abs(resids)) #print newinds #raise SystemExit #newind = np.argmax(np.abs(resids)) newind = newinds[-1] i = 1 addknot = True while newind in knots and np.any(np.abs(knots - newind) <= 4): if i == N: addknot = False break i += 1 newind = newinds[-i] ''' for newind in newinds: if newind in knots: continue elif np.all(np.abs(newind-knots)<=1): continue print newind break ''' if addknot: #print newind knots = np.sort(np.concatenate((knots, [newind]))) else: break resids = yshift - ytemp rms_resids = u.RMS(resids) tdata = tdata[:-1] #yshift = yshift[:-1] ytemp = ytemp[:-1] #yshift = np.roll(yshift,-shift) ytemp = np.roll(ytemp, -shift) ytemp /= np.max(ytemp) return ytemp
def spline_smoothing(self,sigma=None,lam=None,**kwargs): """ Cubic Spline Interplation sigma: phase bin error bars lam: (0,1], 1 = maximize fitting through control points (knots), 0 = minimize curvature of spline """ tdata = self.bins ydata = u.normalize(self.data,simple=True) N = len(ydata) noise = self.getOffpulseNoise() if lam is None or (lam > 1 or lam <= 0): lam = 1-noise**2 mu = 2*float(1-lam)/(3*lam) ### Define knot locations # Rotate the pulse so the peak is at the edges of the spline shift = -np.argmax(ydata) yshift = np.roll(ydata,shift) # Add periodic point tdata = np.concatenate((tdata,[tdata[-1] + np.diff(tdata)[0]])) yshift = np.concatenate((yshift,[yshift[0]])) knots = u.subdivide(tdata,yshift,noise,**kwargs) knots = np.array(np.sort(knots),dtype=np.int) knots = np.concatenate(([0],knots,[N])) #Add endpoints if sigma is None: setsigma = True #for passnum in range(2): while True: Nknots = len(knots) Narcs = Nknots-1 t = np.array(tdata[knots],dtype=np.float) # Determine the knot y-values. y = np.zeros_like(t) y[0] = yshift[0] y[-1] = yshift[-1] for i in range(1,len(knots)-1): knotL = knots[i-1] knotR = knots[i+1] dt = tdata[knotL:knotR] dy = yshift[knotL:knotR] p = np.polyfit(dt,dy,3) #Fit a preliminary cubic over the data to place the point. f = np.poly1d(p) y[i] = f(tdata[knots[i]]) if setsigma: sigma = np.ones(len(y),dtype=np.float) Sigma = np.diag(sigma[:-1]) #matrix # Smoothing with Cubic Splines by D.S.G. Pollock 1999 h = t[1:]-t[:-1] r = 3.0/h f = np.zeros_like(h) p = np.zeros_like(h) #q = np.zeros_like(h) p[0] = 2*(h[0] + h[-1]) #q[0] = 3*(y[1] - y[0])/h[0] - 3*(y[-1] - y[-2])/h[-1] #note the indices f[0] = -(r[-1]+r[0]) for i in range(1,Narcs): p[i] = 2*(h[i] + h[i-1]) #q[i] = 3*(y[i+1] - y[i])/h[i] - 3*(y[i] - y[i-1])/h[i-1] f[i] = -(r[i-1]+r[i]) # Build projection matrices R = np.zeros((Narcs,Narcs)) Qp = np.zeros((Narcs,Narcs)) for i in range(Narcs): #for j in range(Narcs): # if i == j: R[i,i] = p[i] Qp[i,i] = f[i] if i != Narcs -1: R[i+1,i] = h[i] R[i,i+1] = h[i] Qp[i+1,i] = r[i] Qp[i,i+1] = r[i] R[0,-1] = h[-1] R[-1,0] = h[-1] Qp[0,-1] = r[-1] Qp[-1,0] = r[-1] Q = np.transpose(Qp) A = mu*np.dot(np.dot(Qp,Sigma),Q) + R b = np.linalg.solve(A,np.dot(Qp,y[:-1])) d = y[:-1] - mu*np.dot(np.dot(Sigma,Q),b) a = np.zeros(Narcs) c = np.zeros(Narcs) i = Narcs-1 a[i] = (b[0] - b[i])/(3*h[i]) for i in range(Narcs-1): a[i] = (b[i+1] - b[i])/(3*h[i]) i = Narcs-1 c[i] = (d[0] - d[i])/h[i] - a[i]*h[i]**2 - b[i]*h[i] for i in range(Narcs-1): c[i] = (d[i+1] - d[i])/h[i] - a[i]*h[i]**2 - b[i]*h[i] # Build polynomials S = [] for i in range(Narcs): S.append(np.poly1d([a[i],b[i],c[i],d[i]])) ytemp = np.zeros_like(yshift) for i in range(Narcs): ts = np.arange(t[i],t[i+1]) hs = ts-t[i] yS = S[i](hs) ytemp[int(t[i]):int(t[i+1])] = yS ytemp[-1] = ytemp[0] resids = yshift-ytemp #print resids,noise rms_resids = u.RMS(resids) #inds = np.where(np.abs(resids)>4*rms_resids)[0] inds = np.where(np.logical_and(yshift>3*noise,np.abs(resids)>4*rms_resids))[0] #require the intensity to be "significant", and the residuals if len(inds) == 0: break #newinds = np.sort(np.abs(resids)) newinds = np.argsort(np.abs(resids)) #print np.argmax(np.abs(resids)) #print newinds #raise SystemExit #newind = np.argmax(np.abs(resids)) newind = newinds[-1] i = 1 addknot = True while newind in knots and np.any(np.abs(knots-newind)<=4): if i == N: addknot = False break i+=1 newind = newinds[-i] ''' for newind in newinds: if newind in knots: continue elif np.all(np.abs(newind-knots)<=1): continue print newind break ''' if addknot: #print newind knots = np.sort(np.concatenate((knots,[newind]))) else: break resids = yshift-ytemp rms_resids = u.RMS(resids) tdata = tdata[:-1] #yshift = yshift[:-1] ytemp = ytemp[:-1] #yshift = np.roll(yshift,-shift) ytemp = np.roll(ytemp,-shift) ytemp /= np.max(ytemp) return ytemp