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+--- Thread: Vector or list to Number "conversion" (SOLVED.) (/thread-3437.html)
Vector or list to Number "conversion" (SOLVED.) - Spybot - 03-20-2015 03:38 AM
Hi Guys!
I'm trying to compare the numeric value of two objects, one is a vector with only one numeric value and the other is a real number; [1/2]==0.5 the Hp Prime returns a zero.
I searched this forum and the UG. for a command that takes the [1/2] out of the brackets so I can compare them, but I found nothing.
this vector [1/2] is the result of solving an equation using the SOLVE command.
what can I do to make the caparison a true statement?
Thank you.
RE: Vector or list to Number "conversion" - Angus - 03-20-2015 09:46 AM
If I define
result:=[1/2]
and do result(1)==0.5 it works on my emulator. You can access a list or vector by round brackets. First element index 1.
RE: Vector or list to Number "conversion" - cyrille de brébisson - 03-20-2015 10:34 AM
Hello,
Are you in CAS or Home?
In home, assuming that your vector is stored in a variable (vec for example), doing EVAL(vec(1))==0.5 will do the trick.
Cyrille
RE: Vector or list to Number "conversion" - DrD - 03-20-2015 10:59 AM
Perhaps a "List" approach might be useful?
mat2list([1/2]) == 1/2 => {1}
mat2list([1/2, 1/4, 1/2]} == 1/2 => {1, 0, 1}
Using the list facility the test applies to one (or more) elements, without referencing a specific element number.
-Dale-
RE: Vector or list to Number "conversion" - salvomic - 03-20-2015 11:24 AM
(03-20-2015 03:38 AM)Spybot Wrote: [size=large]
Hi Guys!
I'm trying to compare the numeric value of two objects, one is a vector with only one numeric value and the other is a real number; [1/2]==0.5 the Hp Prime returns a zero.
...
(03-20-2015 09:46 AM)Angus Wrote: If I define
result:=[1/2]
and do result(1)==0.5 it works on my emulator. You can access a list or vector by round brackets. First element index 1.
rigorously speaking, a vector with only one component is always a vector, non a real...
So, TYPE([½])= 4 (matrix or vector), and type([½]) = DOM_LIST, and in fact is also a list)
You must use [½](1) to get a value 0.5, and then
type([½](1)) = DOM_RAT and TYPE(...) = 0, a real
I hope this could help you.
Salvo
RE: Vector or list to Number "conversion" - Spybot - 03-21-2015 06:40 AM
All You Guys provided Great solutions!
PROBLEM SOLVE!!!
Thank you Guys!