Re: [HP-Prime xcas] operations with complex numbers & BUGs Message #8 Posted by CompSystems on 8 Sept 2013, 5:41 p.m., in response to message #7 by Gilles Carpentier
Hello, sorry for my bad English
A informatic "bug" is very general =(, use best expressions as requirement, improvement, optimization =) OK ...
...
for example, if there is a flag that says TEXT BOOK, then all should work as pretty print: history, entry line, program editor etc
piecewise template put pretty print on entry line, but them from history to entry line is displayed as a line of text =(, improve this in the next version =)
.5 from history to entry line is displayed as 0.5, then why not also put as 0.5 within the history?
1/3 = 0.3333....
http://www.wolframalpha.com/input/?i=1%2F3
Quote:
However I agree that the polar_coordinate command is strange at least. It returns a kind of list of 2 elements when you expect a polar representation of the object. You get the lentgh and the angle between [] but can't do any calculation with this.
completely agree
a function is useful when I can operate on it, a [#, #] does not say anything, is a list?, a vector?, a array?, a matrix?, a poly?, a set? ...?, while [#, <_#] is a vector in cylindrical coordinates or a complex number in polar form =)
I know the answer history within the polar form, but a program can not determine, CAS has no intelligence like ours
I have to create new functions to resolve the ambiguity of the current version of CAS, redo the sum, mult, div, etc of complex numbers
the solution for BUG is simply incorporating a prefix to the second element of the container, it is difficult to do this? [#, <_#]
///
one of the feature that like much in the series HP48, was handling complex numbers in polar form
///
(1,1) + (3+4*i) => 4+5*i
(1.1) is ugly, but more easily operable
//
TIM
Quote:
When the user gives invalid or incorrectly formatted input, and the device returns something unexpected, how is that classified? If they give valid input, but it represents something different then what they imagine it represents and the result is different, how is that classified?
IS CLASSIFIED AS THE CAS DOES NOT DETECT validity ARGUMENT IMPLIES THAT THE USER IS EXPERT IN HANDLING THE CALCULATOR
If you interpret the following expression as polynomial
[ 1, 2 ] + [ 3, 4, 5, 6 ]
The CAS return
[ 4, 6, 5, 6 ]
is that correct? NO, then use a single object container [ ] creates ambiguity
What did the author of xcas to eliminate ambiguity was put a prefix to container poly1[] // OK =)
poly1[ 1, 2 ] + poly1[ 3, 4, 5, 6 ]
The CAS return
poly[ 3, 4, 6, 8 ] // OK
also must do to list, vectors and matrices, are agree or not?
list[ 1, 2 ] + list[ 3, 4, 5, 6 ]
The CAS return
[ 4, 6, 5, 6 ] // OK can be set with zeros (right) valid
but
vec[ 1, 2 ] + vec[ 3, 4, 5, 6 ]
The good CAS return
"invalid dim"
mat[[ 1, 2 ]] + mat[[ 3, 4, 5, 6 ]]
The good CAS return
"invalid dim"
///
The HP-Prime for differentiating sets incorporates prefixes set to container []
set[a,a,EE,o,u,i,a] return [ a, e, i, o, u ] eliminates repetitions // OK
what happens if you do not put the prefix set[]
[a,a,EE,o,u,i,a] return [a,a,EE,o,u,i,a]
many have reported BUGs that are solved by adding a prefix to vectors and matrices
Edited: 9 Sept 2013, 7:18 a.m. after one or more responses were posted
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