Re: Reading records from file and sorting

El dc 01 de 11 del 2006 a les 15:18 +0000, en/na George Sakkis va escriure:

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Why this is too specific or error-prone?

Because it 1. repeats the field types 2. requires adding up the length of all previous fields as offset.

If you're not convinced yet, try writing this in less than 3 seconds ;-): records = N.fromfile(a_file, dtype=N.dtype('i2,i4,f4,S5,B,Q')) records_by_f5 = ??

Ah, I see your point :)

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I think your solution is quite good.If what you want is a more compact way to write the above, you can try with:

In [56]:records=numpy.array([(1,1),(0,2)], dtype="i2,i4") In [57]:records[records['f0'].argsort()] Out[57]: array([(0, 2), (1, 1)], dtype=[('f0', '

Ah, much better; I didn't know you can index a normal array (not recarray) by label. Now, if there's a way to do the sorting in place (records.sort('f1') doesn't work unfortunately), that would be perfect.

Yes, I agree that having the possibility to do records.sort('f1') would be a great addition (both in terms of usability but also efficiency). Cheers, -- Francesc Altet | Be careful about using the following code -- Carabos Coop. V. | I've only proven that it works, www.carabos.com | I haven't tested it. -- Donald Knuth ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642