On 8/17/2010 11:53 AM, Nikolaus Rath wrote: > I want to find the first i such that x[i]< y and x[i+1]>= y. Is there > a way to do this without using a Python loop? argmax? (to get i+1): >>> d = np.linspace(0,10,101) >>> x = np.sin(d) >>> np.argmax(x>=0.5) 6 fwiw, Alan Isaac