On 25-Jan-07, at 5:54 PM, Miller, Raul D wrote:
dydre wrote:
1. The notation J layers many things in unique ways and
they are not completely documented.
I don't know what this means.
(I know what 'needs to be documented' would mean, but I
do not know how to distinguish between contexts where the
above is an issue and where it is not an issue.)
For example - a few terms from the J Vocabulary:
< Box • Less Than
<. Floor • Lesser Of (Min)
<: Decrement • Less Or Equal
> Open • Larger Than
>. Ceiling • Larger of (Max)
>: Increment • Larger Or Equal
_ Negative Sign / Infinity
_. Indeterminate
_: Infinity
+ Conjugate • Plus
+. Real / Imaginary • GCD (Or)
+: Double • Not-Or
* Signum • Times
*. Length/Angle • LCM (And)
*: Square • Not-And
- Negate • Minus
-. Not • Less
-: Halve • Match
% Reciprocal • Divide
%. Matrix Inverse • Matrix Divide
%: Square Root • Root
^ Exponential • Power
^. Natural Log • Logarithm
^: Power (u^:n u^:v)
$ Shape Of • Shape
$. Sparse
$: Self-Reference
Can you show me another language where the same sets of concepts are
mapped to equivalent words - for example in C++ or Java or any other
language of your choosing, is there a concept such as Double and Not-
Or combined in a single word?
This is not a criticism of J. Once understood, there is power in the
layering of the concepts. However, many concepts of this nature in
Dr Iverson's Dictionary of J language are left as an exercise to the
student which I must say is not without its charm. However, having a
more complete reference might be more expedient for some students.
(c) Primitives of APL did allow a level of abstraction that did
simplify underlying complexity. J permits you to compress complex
ideas but it is not necessarily by simplifying an underlying
complexity.
I don't know what this means.
--
Raul
Sorry I am too busy to create a good example of this. I do not have
an APL environment on my machine. So far I am using J in a J console
under my terminal window because I find it easier
than the provided environment that can cause overwriting in the log.
This brings up another point for me. I imagine people who actual use
J have devised an environment for themselves but I have nothing
equivalent to the simple concept of saving an APL workspace.
Donna
[EMAIL PROTECTED]
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
