Thank you sir: thank you....very much for ur time and consideration..................
On Fri, Apr 29, 2011 at 9:11 PM, Christopher Barker <[email protected]>wrote: > On 4/29/11 12:31 AM, pratik wrote: > > On Friday 29 April 2011 12:56 PM, dileep kunjaai wrote: > >> Dear sir, > >> I am trying to make an array of varies from -60 to 90 with difference > >> 0.25. I tried the following command ... > > >> >>import numpy as N > >> lat=N.array(xrange(-6000, 9000, 25), dtype=float) > >> print lat/100 > > xrange() (or range(), or np.arange()) is almost never the right solution > for floating point ranges, due to the intricacies of floating point > precision. > > > lat =numpy.mgrid[-60:90:.25] > > or np.linspace: > > np.linspace(-60,90,((60.+90.)*4. + 1)) > > ((60.+90.)*4. + 1) is the number of points you want -- the +1 because > you want both end points. > > mgrid is usually used for 2-d (or higher) grids, though it looks like it > makes sense for this use, too, though note that it doesn't give you both > endpoints in this case. From the docs: > > """If the step length is not a > complex number, then the stop is not inclusive. > """ > > and an example: > > In [15]: np.mgrid[-1:3:.25] > Out[15]: > array([-1. , -0.75, -0.5 , -0.25, 0. , 0.25, 0.5 , 0.75, 1. , > 1.25, 1.5 , 1.75, 2. , 2.25, 2.5 , 2.75]) > > I think this is too bad, actually, because we're back to range()-type > tricks to get the end point: > > In [20]: np.mgrid[-1:3.25:.25] > Out[20]: > array([-1. , -0.75, -0.5 , -0.25, 0. , 0.25, 0.5 , 0.75, 1. , > 1.25, 1.5 , 1.75, 2. , 2.25, 2.5 , 2.75, 3. ]) > > > -Chris > > > > -- > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > [email protected] > _______________________________________________ > NumPy-Discussion mailing list > [email protected] > http://mail.scipy.org/mailman/listinfo/numpy-discussion > -- DILEEPKUMAR. R J R F, IIT DELHI
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