Mailman 3 June 2004 - NumPy-Discussion

Re: Your bill
by numpy-discussion＠lists.sourceforge.net 01 Jun '04

01 Jun '04

------------------ Virus Warning Message (on octopussy) Found virus WORM_NETSKY.D in file your_bill.pif The uncleanable file is deleted. ---------------------------------------------------------

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RE: [Numpy-discussion] searchsorted
by Nadav Horesh 01 Jun '04

01 Jun '04

-----Original Message----- From: Perry Greenfield [mailto:perry@stsci.edu] Sent: Tue 01-Jun-04 19:16 To: Nadav Horesh; numpy-discussion Cc: Subject: RE: [Numpy-discussion] searchsorted Nadav Horesh writes > I am currently working on a simulation that makes a heavy use of > searchsorted. But it does not precisely fit to what I need --- if a > value v is between p and q searchsorted returns the index of q, while > what I need is the index of p. > > Currently my solution is to turn to floating points numbers: > > ====================================== > > Python 2.3.4 (#1, May 31 2004, 09:13:03) > [GCC 3.4.0] on linux2 > Type "help", "copyright", "credits" or "license" for more information. > from numarray import * > > bins = array((0,10,20,30)) > val = array((10, 15)) > searchsorted(bins, val) > array([1, 2]) # I really would like to get array([1, 1]) > > # Here is the trick: > > fb = bins - 0.1 > fb > array([ -0.1, 9.9, 19.9, 29.9]) > > searchsorted(fb, val) - 1 > array([1, 1]) # That's it! > This is only approximate, right? If val = array([9.95, 15]) you will get the wrong answer won't you? > ============================================ > > My questions are: > > 1. Is there a more elegant solution? > 2. I am thinking of letting "searchsorted" return a second boolean > array which has the value True for every exact match: > >>> searchsorted(bins, val) > >>> [array([1, 2]), array([1, 0], type=Bool)] > Any comments? > > Nadav. > To get the latter, you could so something like ind = searchsorted(bins, val) neq_mask = bins[ind]-val ind[neq_mask] -= 1. # well, you need to handle where ind = 0 and # is not equal as well Would that suffice? Perry ------------------------------------- Got the idea, the line should be really: ind = ind - (bins[ind] != val) You helped a lot. Thank you very much, Nadav.

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Undeliverable: Re: Your bill
by System Administrator 01 Jun '04

01 Jun '04

Your message To: jacques.heliot(a)framatome-anp.com Subject: Re: Your bill Sent: Wed, 2 Jun 2004 08:58:40 +0200 did not reach the following recipient(s): jacques.heliot(a)framail.framatome-anp.com on Wed, 2 Jun 2004 08:58:45 +0200 The recipient name is not recognized The MTS-ID of the original message is: c=fr;a= ;p=fragroup;l=FPARI01MXB0406020658LWFQLW5H MSEXCH:IMS:FRAGROUP:FRAANP-FR-PARIS-PARIS:FPARI01MXB 0 (000C05A6) Unknown Recipient

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searchsorted
by Nadav Horesh 01 Jun '04

01 Jun '04

I am currently working on a simulation that makes a heavy use of searchsorted. But it does not precisely fit to what I need --- if a value v is between p and q searchsorted returns the index of q, while what I need is the index of p. Currently my solution is to turn to floating points numbers: ====================================== Python 2.3.4 (#1, May 31 2004, 09:13:03) [GCC 3.4.0] on linux2 Type "help", "copyright", "credits" or "license" for more information. from numarray import * bins = array((0,10,20,30)) val = array((10, 15)) searchsorted(bins, val) array([1, 2]) # I really would like to get array([1, 1]) # Here is the trick: fb = bins - 0.1 fb array([ -0.1, 9.9, 19.9, 29.9]) searchsorted(fb, val) - 1 array([1, 1]) # That's it! ============================================ My questions are: 1. Is there a more elegant solution? 2. I am thinking of letting "searchsorted" return a second boolean array which has the value True for every exact match: >>> searchsorted(bins, val) >>> [array([1, 2]), array([1, 0], type=Bool)] Any comments? Nadav.

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