Thanks Olivier, Your suggestion gets me a little closer to what I want, but doesn't quite work. Replacing the conversion with
c = lambda x:np.cast[np.complex64](complex(*eval(x))) b = np.genfromtxt(a,converters={0:c, 1:c, 2:c, 3:c},dtype=None,delimiter=18,usecols=range(4)) produces [[(-3.97000002861-5.03999996185j) (-1.1318000555-2.56929993629j) (-4.60270023346-0.142599999905j) (-1.42490005493+1.73300004005j)] [(-5.4797000885+0j) (1.85850000381-1.5501999855j) (4.41450023651-0.763800024986j) (-0.480500012636-1.19760000706j)] [0j (6.26730012894+0j) (-0.45039999485-0.0289999991655j) (-1.34669995308+1.65789997578j)] [0j 0j (-3.5+0j) (2.56189990044-3.37080001831j)]] which is not yet an array of complex numbers. It seems close to the solution though. Gary On Fri, Jun 17, 2011 at 8:40 PM, Olivier Delalleau <sh...@keba.be> wrote: > If I understand correctly, your error is that you convert only the second > column, because your converters dictionary contains a single key (1). > If you have it contain keys from 0 to 3 associated to the same function, it > should work. > > -=- Olivier > > 2011/6/17 gary ruben <gru...@bigpond.net.au> >> >> I'm trying to read a file containing data formatted as in the >> following example using genfromtxt and I'm doing something wrong. It >> almost works. Can someone point out my error, or suggest a simpler >> solution to the ugly converter function? I thought I'd leave in the >> commented-out line for future reference, which I thought was a neat >> way to get genfromtxt to show what it is trying to pass to the >> converter. >> >> import numpy as np >> from StringIO import StringIO >> >> a = StringIO('''\ >> (-3.9700,-5.0400) (-1.1318,-2.5693) (-4.6027,-0.1426) (-1.4249, 1.7330) >> (-5.4797, 0.0000) ( 1.8585,-1.5502) ( 4.4145,-0.7638) (-0.4805,-1.1976) >> ( 0.0000, 0.0000) ( 6.2673, 0.0000) (-0.4504,-0.0290) (-1.3467, 1.6579) >> ( 0.0000, 0.0000) ( 0.0000, 0.0000) (-3.5000, 0.0000) ( 2.5619,-3.3708) >> ''') >> >> #~ b = np.genfromtxt(a,converters={1:lambda >> x:str(x)},dtype=object,delimiter=18) >> b = np.genfromtxt(a,converters={1:lambda >> x:complex(*eval(x))},dtype=None,delimiter=18,usecols=range(4)) >> >> print b >> >> -- >> >> This produces >> [ (' (-3.9700,-5.0400)', (-1.1318-2.5693j), ' (-4.6027,-0.1426)', ' >> (-1.4249, 1.7330)') >> (' (-5.4797, 0.0000)', (1.8585-1.5502j), ' ( 4.4145,-0.7638)', ' >> (-0.4805,-1.1976)') >> (' ( 0.0000, 0.0000)', (6.2673+0j), ' (-0.4504,-0.0290)', ' (-1.3467, >> 1.6579)') >> (' ( 0.0000, 0.0000)', 0j, ' (-3.5000, 0.0000)', ' ( 2.5619,-3.3708)')] >> >> which I just need to unpack into a 4x4 array, but I get an error if I >> try to apply a different view. >> >> thanks, >> Gary >> _______________________________________________ >> NumPy-Discussion mailing list >> NumPy-Discussion@scipy.org >> http://mail.scipy.org/mailman/listinfo/numpy-discussion > > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > > _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion