[Numpy-discussion] one-offset arrays

Travis Oliphant oliphant.travis at ieee.org
Tue Aug 28 15:42:17 EDT 2001

On Tue, 28 Aug 2001, Eric Nodwell wrote:
> Does anyone have a simple method of using one-offset arrays?
> Specifically, can I define an array "a" so that a[1] refers to the
> first element?

Inherit from the UserArray and redefine slicing to your hearts content.

> Without one-offset indexing, it seems to me that Python is minimally
> useful for numerical computations. Many, perhaps the majority, of
> numerical algorithms are one-indexed. Matlab for example is one-based
> for this reason.  In fact it seems strange to me that a "high-level"
> language like Python should use zero-offset lists.

Wow, that is a pretty condescending-sounding statement, though I'm sure you 
didn't mean it that way.  Python is indeed being used for quite serious 
numerical computations.  I have been using Python for quite some time for 
Numerical work and find it's zero-based indexing combined with the 
leave-last-one-out slicing notation to be much more convenient.  

It is different from MATLAB but that hardly makes it less useful as I suspect 
you'd agree after trying it out for awhile.

What is your application domain that so requires 1-based indexing.

Travis E. Oliphant, Ph.D.
Assistant Professor
Brigham Young University
Provo, UT 84602
(801) 378-3108
oliphant.travis at ieee.org

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