On 7/3/06, Keith Goodman <[EMAIL PROTECTED]> wrote: > I have a list x > > >> x > [[1, None], [2, 3]] > > that I generate outside of numpy (with plain python). What is the best > way to convert x into an array? This doesn't work > > >> asarray(x) > > array([[1, None], > [2, 3]], dtype=object) <-- I'm hoping for something like > dtype=float64 > > Is there something better than None to represent missing values so > that when I convert to numpy arrays (actually matrices) I'll be all > set? (I could use -99, but that would be even more embarrassing than > my python skills.) > > If there is nothing better than None, what's a fast way to take care > of the None's if x is faily large?
You might want to have a look at the masked array module in numpy (numpy.ma). The following example might help to get you started. >>> import numpy as N >>> x = [[1, None], [2, 3]] >>> m = N.ma.array(x, mask=N.equal(x, None)) >>> print m [[1 --] [2 3]] Cheers, Tim > > 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 > _______________________________________________ > Numpy-discussion mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/numpy-discussion > 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 _______________________________________________ Numpy-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/numpy-discussion
