I have a degree in economics and have been working as a software developer for
18 years. My current job title is Technical Consultant II but I primarily do
back-end and data intensive computations where I use J. All of the people I
work with have a degree in computer programming (I was the odd one in the pack
coming from a business course) so it's really nice to know that a lot of J
users have a background in economics and some are dyslectic like me ... I do
hope that I'm the only one who's really bad in arithmetic though.
On the 2nd quarter of 2004, our company had a standardization review for the
whole technical team. Although it covered a lot of things, which eventually led
us to the development of our in-house RAD tool, one of the most argued topic
was the use of 0 or 1 as the index origin. A lot of research was put on the
table but in the end, 1 was the index origin. The outcome of this discussion
led to the creation of libraries in the programming language that we use and
our standard J libraries contains code snippets such as this:
from
+-+-+-------------------------------------+
|4|:|NB. indices-of-elements (IO=1) from y|
| | |(_1 + x) { y |
+-+-+-------------------------------------+
int
+-+-+----------------------------------+
|3|:|NB. integers from 1 to y with IO=1|
| | |1+ i. y |
+-+-+----------------------------------+
Column selection looks like this:
NB. Create the test data, notice the numbers start with 1
[test=. int 3 5
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
NB. Retried the 2nd column
2 colsfrom test
2 7 12
NB. Retrieve the 2nd and 1st rows
2 1 rowsfrom test
6 7 8 9 10
1 2 3 4 5
Since I qualify, my answer is that a fixed value of 0 is not a hindrance to my
work. J is versatile enough that we can create libraries where we can choose
the index origin.
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Roger Hui
Sent: Saturday, July 24, 2010 9:17 PM
To: Programming forum
Subject: [Jprogramming] index origin 0
I have been asked by some APL colleagues about index origin 0 in J. The
question is, does the choice of a fixed value of 0 for index origin a hindrance
to your work? The question is specifically addressed to "ordinary domain
experts", people with no software engineering in their background and are not
professional mathematicians.
In case you did not know, in APL there is a choice known as the index origin,
controlled by the variable quad-io, of counting from 1 instead of from 0,
affecting the left argument of { and the result of i. , among other things.
I will say no more than this to avoid biasing your answers.
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