Post Reply 
a degree radians question....
10-23-2017, 10:07 PM
Post: #6
RE: a degree radians question....
(10-23-2017 05:05 PM)Tim Wessman Wrote:  Its nothing to do with lacking the understanding that it is important, nor in lacking the will to do so.

The CAS would need extensive modification and is inherently incompatible with the concept of angular values as implemented in Prime or previous calculators. There are plenty of things on the list to work on, would take an incredible amount of time and effort, and this is not higher then the others in priority.

Since I have no access to the source code of Home or the keyboard I/O, lexical analyzer and parser, I cannot say how hard it is to do this and I can imagine it could be tricky, but since the functions are there in CAS and Home just not assigned to the <angle>/< ° ‘ “ > symbols and buttons nor recognized (consistently) by the parser, I imagined it could be relatively easy as well... at least I hoped so writing my suggestion before…

Anyway, naively, I would think it would just be:

In CAS: as the user types poll key board
a) if <angle> pressed and polar/rectangular coordinates are present, then invoke existing appropriate convert function (that already exist in CAS) and present result EXACT. If not, just allow the <angle> token
In CAS and Home: as the user types poll key board
b) if < ° ‘ “ > pressed, tokenize ° ‘ “ and the symbols/numbers between them (alternatively this can be done on <enter>)

For parsing a full line when the user presses <enter> key
1) Changing/adapting the lexical analyzer to recognize and tokenize the <angle> and the < ° ‘ “ > symbol (as well as the symbols/numbers around them) properly in the lexical context of the whole input line.
2) Adding/adapting the BNF/EBNF rules for how to syntactically interpret the statement around the <angle> and < ° ‘ “ >. Parse the whole line to produce the AST in a standard form that CAS or Home already can understand (depending on the view you are in). Since the actual algebra code is already there, it could be simple mapping to an AST form that is already understood (for CAS this could simply be rectangular form since CAS can handle rectangular form algebraically)
3) Invoking CAS or Home engine (passing the AST in the standard form). Wait for it to return…
4) When result return, you could choose to always show in rectangular form.
5) Return to allow user to use key board
6) Allow user to swap between the forms using a) above (home already working)
Probably I am too simplistic here making too many assumptions on the internals, but it looked straight forward to me…

Understand there must be many priorities HP need to balance, but still, this would be an important one, not only to Engineering students, but also to Pre calc, AP calc and AP physics high school students.

Thanks for reading
Find all posts by this user
Quote this message in a reply
Post Reply 


Messages In This Thread
RE: a degree radians question.... - Anders - 10-23-2017, 03:39 PM
RE: a degree radians question.... - Anders - 10-23-2017 10:07 PM
RE: a degree radians question.... - Anders - 10-23-2017, 10:44 PM



User(s) browsing this thread: 1 Guest(s)