[Numpy-discussion] Re: comments on the Numerical Python manual
L. Busby
busby at icf.llnl.gov
Thu Oct 19 15:27:48 EDT 2000
Fred -
I'm forwarding your mail on to numpy-discussion at lists.sourceforge.net,
which I believe is the proper venue to deal with your comments. If
the current Numerical Python manual directed you to
support at icf.llnl.gov for support-related questions, that also needs to
be updated.
Thank you - Lee Busby
=======================================================================
From: Fred Yankowski <fred at ontosys.com>
To: support at icf.llnl.gov
Subject: comments on the Numerical Python manual
Greetings,
I'm learning NumPy by working through the "Numerical Python" manual
(Oct 9, 2000 version). So far the manual has been a great
introduction to the software and I really appreciate the work of the
authors in providing it.
I have found a couple of problems in the text, as follows:
On page 4 in section 4, it seems that
>>> vector1 = array((1,2,4,5))
should be the following instead:
>>> vector1 = array((1,2,3,4,5))
On page 48 in section 8, the translation table used in the
"brightening" function acts instead to darken the image. I found that
scaling proportional to a square-root function worked well:
table = (arange(256)**.5 * (255**.5)).astype('b')
One side note: I'm surprised that the coordinate system used by the
NumTut.view function has X axis values increasing to the left. Is
that standard for some graphing systems? I've never worked with such
a system before. Or am I misunderstanding what I'm seeing with view?
I'm basing this on inspection of view(arange(100)**2)) and
view(arange(100)**.5).
--
Fred Yankowski fred at OntoSys.com tel: +1.630.879.1312
Principal Consultant www.OntoSys.com fax: +1.630.879.1370
OntoSys, Inc 38W242 Deerpath Rd, Batavia, IL 60510, USA
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