SCOUG-SundialSIG Mailing List Archives

>> Next Message >>

Date:	Fri, 13 Apr 2001 07:40:58 PST
From:	"Lynn H. Maxson" <lmaxson@pacbell.net >
Reply-To:	scoug-sundialsig@scoug.com
To:	Scoug Sundial Sig <scoug-sundialsig@scoug.com >
Subject:	SCOUG-SundialSIG: Lesson plan

Content Type: text/plain

I don't want to get off on a tangent by offering a position with
respect to a subject which goes where the participants have no
desire to follow. When someone says to me that they have an
interest in "equations" in Mesa that they have gone beyond data
entry and into data processing. Data processing involving
equations, i.e. compositions of operators and operands, means
programming, particularly if it also involves the use of logical
functions.

I'm inclined to step back to the data entry stage to point out
that spreadsheets and relational databases deal with structured
data, homogeneous (same data type) and non-homogeneous (mixed data
types), encapsulated in "flat files". In my opinion there no
sense in talking about flat files without including at least a
definition of non-flat files, i.e. those with variable number of
repeating groups. That means defining a data group as well.

From that point we can talk about flat files in terms of fixed
length records (rows) consisting of multiple fields (columns).
Now we can discuss how we select among the rows and within them
the columns. This deals with naming conventions, using either
symbolic or indexing references.

With our reference scheme in place we now have means of naming
operands, either data element (specific row and column in a
spreadsheet) or data aggregate (either a column or row vector
defined by a contiguous range of rows within a column or columns
within a row).

With this in place we can introduce the use of a label variable in
MESA which defines a data aggregate in terms of the range of
application. We should discuss the use of this label in an
equation, its maintenance, and how it differs in terms of
maintenance from a similar use in a relational database using SQL.

To ease the ability of expressing this I'm considering also
introducing APL as a documentation technique as well a programming
language. Through this means a general and, I hope, gentle
introduction into programming, something that deals with matching
the solution set to the problem set through analysis of the
problem set leading to the design of the solution set and then the
construction of that design into the programming languages
represented by formulas in spreadsheets, queries in SQL, and
processing statements in a procedural programming language.

I offer it here because it would never occur to the programming
SIG that programming, the matching of a solution set to the
problem set, involves more than diddling with the solution set.

Thus I offer this test of our mailing list, one, to get your
feedback prior to our meeting this month, and, two, to see if we
can use this to fill the intervals usefully between the meetings.
Also bear in mind that we can use this mailing list to announce
chat sessions that we might schedule from time to time.

=====================================================

To unsubscribe from this list, send an email message
to "steward@scoug.com". In the body of the message,
put the command "unsubscribe scoug-sundialsig".

For problems, contact the list owner at
"rollin@scoug.com".

=====================================================

Return to [ 13 | April | 2001 ]

SCOUG, Warp Expo West, and Warpfest are trademarks of the Southern California OS/2 User Group. OS/2, Workplace Shell, and IBM are registered trademarks of International Business Machines Corporation. All other trademarks remain the property of their respective owners.