From 444d51ceb7857e0be8918f5090298a5431db00c9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Johannes=20Sch=C3=B6nberger?= Date: Thu, 28 Feb 2013 23:18:25 +0100 Subject: [PATCH] Calculate initial guess for closest point on ellipse for speedup --- skimage/measure/fit.py | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/skimage/measure/fit.py b/skimage/measure/fit.py index 232cbde3..ed89c8b8 100644 --- a/skimage/measure/fit.py +++ b/skimage/measure/fit.py @@ -416,10 +416,14 @@ class EllipseModel(BaseModel): residuals = np.empty((N, ), dtype=np.double) + # initial guess for parameter t of closest point on ellipse + t0 = np.arctan2(y - yc, x - xc) - theta + + # determine shortest distance to ellipse for each point for i in range(N): xi = x[i] yi = y[i] - t, _ = optimize.leastsq(fun, 0, args=(xi, yi), Dfun=Dfun, + t, _ = optimize.leastsq(fun, t0[i], args=(xi, yi), Dfun=Dfun, col_deriv=True) residuals[i] = np.sqrt(fun(t, xi, yi))