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CAS Matrix*Vector+Vector addition + const addition and Coefficients fail
In Progress
see https://www.geogebra.org/m/tmakcd2s
Line 4-5 ( only variable y evaluated - missing coeffs z)
q_x:=(-y^(2)) - z^(2) - ((2 * y) * z) + (2 * y) - 1
cB:=Coefficients(q_x) ==>cB:={(-1), ((-2) * z) + 2, (-z^(2)) - 1}
AlgebraView ===> {0, (-1), (-1), (-1), 0, 0, (-2), 0, 2, 0} correct
Line 26 (a_0=1 got 5 - have to convert a to list, should be posible to compute Matrix*Vector+Vector?
X M X + a X + a_0 ===> x^(2) + (3 * y^(2)) - z^(2) - ((4 * x) * y) - ((2 * y) * z) + (2 * x) - (2 * y) - 5
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Sorry, Coefficients(quadric) only works in the Algebra View (as you've noticed).
For the other problems please say clearly
* which row is wrong
* what you get
* what you'd like to get
I see,
to Coefficents I have added a additional x^2 to force a correct result.
----
see Line 24 and Line 27
If I add a_0 : X M X + a X + a_0 ===> I got a -5 and not the value of a_0=-1
even
X M X + a X + 1
>x² + 3y² - z² - 4x y - 2y z + 2x - 2y + 5
Addition of Matrix*Vektor+Const goes wrong
I am missing a clear statement to convert list <==> vector, vector <==> list
list((1,2,3))={1,2,3}
vector({1,2,3})=(1,2,3)^T
Point({1,2,3})=(1,2,3)
it's pretty horrible to handle homogeneous coordinates in CAS
and Vector <==> Point
v:=Vector( Q)
is possible, but
V:=Point(v)
not....
V:=Point(v) <-----> V=(0,0,0)+v
v <-----> {x(v),y(v),z(v)}
Of course you can construct a workaround for almost everything, but in the sense of a clear and readable code it would be desirable to have explicit instructions?
BTW: the functions x(),y(),z() have a low half-life in CAS - and yes, I have workaround for ...
big ilogical bug
he hecho algunas cuentas y en el caso
X M X 3+6+1+2 lo que se calcula realmente es (X M X+9) 12 donde 9=3+6 y 12=3+6+1+2
he probado con otros numeros diferentes y la cuenta se hace de la misma manera
al menos sigue una logica erronea
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